Cellular digital mobile radio system and method of transmitting information in a digital cellular mobile radio system

Abstract

The invention relates to a cellular digital mobile radio system including base stations (B m , B n ) and mobile stations (MS 1 , MS 2 ) with transmitters and receivers. The invention also relates to a method of transmitting message information digitally between mobile and base stations in such a system. In accordance with the invention, at least two base station transmitters (B ma , B mb , P na , B nb ) at a given transmitting distance from each other are assigned to each of certain cells (C m , C n ) within a restricted geographical area. The base station transmitters which are assigned to the same cell transmit digitally modulated radio signals within the same frequency range at least partially simultaneously to the mobile stations of the cell. The radio signals from different base station transmitters associated with the same cell are digitally modulated with the same message information to the mobile stations in the cell. Different base station transmitters ( 9 A, 9 B) preferably transmit the digitally modulated radio signals with the same message information to a given mobile station with a given mutual transmission time shift. Here, the transmission time shift is selected individually for each mobile station, such that corresponding digitally modulated radio signals with the same message information to a given mobile station from different base station transmitters arrive practically simultaneously at the mobile station.

We claim:  
     
       1. A cellular mobile radio system comprising a plurality of mobile stations which are movable within and between a plurality of cells and a plurality of associated base stations assigned to said cells for digital transmission of message information, each of said plurality of base stations and mobile stations having associated therewith a respective set of a transmitter and a receiver so that said message information in the form of radio signals with digital modulation can be communicated therebetween, said radio signals being digitally modulated with said message information within modulation time intervals, each of said receivers including means for reconstructing the digital modulation from corresponding radio signals received within a predetermined reception time interval; said cells and base stations being associated with one another in a manner such that at least two base station transmitters are assigned to each of predetermined cells within a limited geographic area, said at least two base station transmitters being disposed at a predetermined transmitting distance from each other and each operable to transmit segments of digitally modulated radio signals virtually simultaneously and within the same frequency range with identical message information being transmitted by the other of said at least two base station transmitters to mobile stations within a cell to which both of said transmitters are assigned, the digitally modulated radio signals from said at least two base station transmitters having modulation time intervals which are shorter than the time required for radio signals to propagate a distance which is as long as a greatest transmitting distance between two base station transmitters assigned to one cell within said geographic area, wherein 
       said reconstructing means associated with each of said receivers in said plurality of mobile stations operate to reconstruct digital modulation of corresponding radio signals received during a reception time interval which is at least as long as a time required for radio signals to propagate a distance which is as long as said greatest transmitting distance.  
     
     
       2. A cellular mobile radio system as claimed in  claim 1 , further comprising: 
       time measurement means for estimating mutual reception time shifting in a mobile station between digitally modulated radio signals transmitted to said mobile station from a base station transmitter associated with one of said predetermined cells where said mobile station is located, and corresponding digitally modulated radio signals transmitted to said mobile station from another base station transmitter associated with said one of said predetermined cells.  
     
     
       3. A cellular mobile radio system as claimed in  claim 2 , wherein said time measurement means includes arrival time comparison means associated with said mobile station for comparing arrival times for corresponding digitally modulated radio signals transmitted from different base station transmitters associated with said one of said predetermined cells. 
     
     
       4. A cellular mobile radio system as claimed in  claim 2 , wherein said time measurement means includes arrival time comparison means associated with one of said at least two base station transmitters for comparing arrival times for digitally modulated radio signals transmitted from a second mobile station in a second of said predetermined cells and received at different base station transceivers associated with said second of said predetermined cells. 
     
     
       5. A cellular mobile radio system as claimed in  claim 2 , further comprising: 
       transmission time shifting means for mutually time shifting transmission times of said at least two base station transmitters associated with said one of said predetermined cells such that said at least two base station transmitters transmit corresponding digitally modulated radio signals to said mobile station with greater or less mutual transmission time shifting in response to the estimated reception time shifting.  
     
     
       6. A method in a cellular mobile radio system for digitally transmitting message information between a plurality of mobile radio stations and a plurality of base stations associated with respective cells of said cellular mobile radio system, said message information being in the form of digitally modulated radio signals that are transmitted and received by transmitters and receivers respectively associated with each of said plurality of base and mobile stations, said method comprising the steps of: 
       transmitting digitally modulated radio signals with identical message information from at least two base stations associated with the same cell, and located at a predetermined distance from one another, to mobile stations within said cell, the digitally modulated radio signals that are transmitted from one of said base stations having certain segments which are transmitted virtually simultaneously and within the same frequency range as digitally modulated radio signals transmitted from the other of said two base stations;  
       digitally modulating said radio signals at transmission of said message information within modulation time intervals, said modulation time intervals being shorter than the time necessary for radio signals to propagate a distance which corresponds to the greatest transmitting distance between two base stations associated with a cell of said cellular mobile radio system; and  
       reconstructing the digital modulation from corresponding radio signals that are received at a mobile station during a reception time interval, said reception time interval being at least as long as the time required for radio signals to propagate a distance which corresponds to the greatest transmitting distance between said two base stations associated with said cell.  
     
     
       7. A method as claimed in  claim 6 , wherein said digitally modulated radio signals with identical message information are transmitted from different base station transmitters having mutually variable transmission time shifting capabilities to a predetermined mobile station, and further including the step of selecting said mutually variable transmission time shifting so as to counteract differences in propagation time for said digitally modulated radio signals from said different base station transmitters to said predetermined mobile station. 
     
     
       8. A method as claimed in  claim 7  further comprising the steps of: 
       estimating an arrival time shift between said digitally modulated radio signals with said identical message information from said different base station transmitters at said predetermined mobile station;  
       transmitting information relating to the estimated arrival time shift from said predetermined mobile station to at least one base station; and  
       utilizing the estimated arrival time shift for selecting transmission time shifting for at least one base station transmitter.  
     
     
       9. A method as claimed in  claim 7 , further comprising the steps of: 
       estimating a reception time shift between reception by different base station receivers of corresponding radio signals with identical message information from said predetermined mobile station; and  
       utilizing said reception time shift for selecting said transmission time shift for corresponding base station transmitters.  
     
     
       10. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       a plurality of base stations associated with said cells, some of said cells having at least two base stations associated therewith and located a distance from one another to transmit respective radio signals into a cell, which signals are digitally encoded with the same message information and are transmitted at the same frequency and substantially simultaneously with one another, each base station including means for digitally encoding the radio signals with message information, said encoding being carried out with modulation time intervals which are no longer than the time required for audio signals to propagate a distance corresponding to the greatest transmitting distance between two base stations associated with one cell in said system; and  
       a plurality of mobile stations each having means for reconstructing the digital encoding of plural corresponding radio signals respectively received over the same frequency range during a reception time interval from the two base stations associated with a cell, which reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between two base stations associated with a cell.  
     
     
       11. A cellular mobile radio system comprising a plurality of mobile stations which are movable within and between a plurality of cells and a plurality of associated base stations assigned to said cells for digital transmission of message information, 
       
         each of said plurality of base stations and mobile stations having associated therewith a respective set of a transmitter and a receiver so that said message information in the form of radio signals with digital modulation can be communicated therebetween,  
       
       
         said radio signals being digitally modulated with said message information within modulation time intervals, each of said receivers including means for reconstructing the digital modulation from corresponding radio signals received within a predetermined reception time interval;  
       
       
         said cells and base stations being associated with one another in a manner such that at least two base station transmitters are assigned to each of predetermined cells within a limited geographic area,  
       
       
         said at least two base station transmitters being disposed at a predetermined transmitting distance from each other and each operable to transmit segments of digitally modulated radio signals virtually simultaneously and within the same frequency range with identical message information being transmitted by the other of said at least two base station transmitters to mobile stations within a cell to which both of said transmitters are assigned,  
       
       
         the digitally modulated radio signals from said at least two base station transmitters having modulation time intervals which are shorter than the time required for radio signals to propagate a distance which is as long as a greatest transmitting distance between two base stations transmitters assigned to one cell within said geographic area, wherein  
       
       
         said reconstructing means associated with each of said receivers in said plurality of mobile stations operate to reconstruct digital modulation of corresponding radio signals received during a reception time interval which is at least as long as a time required for radio signals to propagate a distance which is as long as said greatest transmitting distance, and  
       
       
         means for handing off a mobile station from one of said at least two base stations to the other of said at least two base stations. 
       
     
     
       12. A cellular mobile radio system comprising a plurality of mobile stations which are movable within and between a plurality of cells and a plurality of associated base stations assigned to said cells for digital transmission of message information, 
       
         each of said plurality of base stations and mobile stations having associated therewith a respective set of a transmitter and a receiver so that said message information in the form of radio signals with digital modulation can be communicated therebetween,  
       
       
         said radio signals being digitally modulated with said message information within modulation time intervals, each of said receivers including means for reconstructing the digital modulation from corresponding radio signals received within a predetermined reception time interval;  
       
       
         said cells and base stations being associated with one another in a manner such that at least two base station transmitters are assigned to each of predetermined cells within a limited geographic area,  
       
       
         said at least two base station transmitters being disposed at a predetermined transmitting distance from each other and each operable radio transmit segments of digitally modulated radio signals virtually simultaneously and within the same frequency range with identical message information being transmitted by the other of said at least two base station transmitters to mobile stations within a cell to which both of said transmitters are assigned,  
       
       
         the digitally modulated radio signals from said at least two base station transmitters having modulation time intervals which are shorter than the time required for radio signals to propagate a distance which is as long as a greatest transmitting distance between two base stations transmitters assigned to one cell within said geographic area, wherein  
       
       
         said reconstructing means associated with each of said receivers in said plurality of mobile stations operate to reconstruct digital modulation of corresponding radio signals received during a reception time internal which is at least as long as a time required for radio signals to propagate a distance which is as long as said greatest transmitting distance; and  
       
       
         means for terminating a radio signal from one of said at least two base stations. 
       
     
     
       13. A method in a cellular mobile radio system for digitally transmitting message information between a plurality of mobile radio stations and a plurality of base stations associated with respective cells of said cellular mobile radio system, 
       
         said message information being in the form of digitally modulated radio signals that are transmitted and received by transmitters and receivers respectively associated with each of said plurality of base and mobile stations, said method comprising the steps of:  
       
       
         transmitting digitally modulated radio signals with identical message information from at least two base stations associated with the same cell, and located at a predetermined distance from one another, to mobile stations within said cell, the digitally modulated radio signals that are transmitted from one of said base stations having certain segments which are transmitted virtually simultaneously and within the same frequency range as digitally modulated radio signals transmitted from the other of said two base stations;  
       
       
         digitally modulating said radio signals at transmission of said message information within modulation time intervals, said modulation time intervals being shorter than the time necessary for radio signals to propagate a distance which corresponds to the greatest transmitting distance between two base stations associated with a cell of said cellular mobile radio system;  
       
       
         reconstructing the digital modulation from corresponding radio signals that are received at a mobile station during a reception time in said reception time interval being at least as long as the time required for radio signals to propagate a distance which corresponds to the greatest transmitting distance between said two base stations associated with said cell; and  
       
       
         handing off a mobile station from one of said at least two base stations to another of said at least two base stations. 
       
     
     
       14. A method in a cellular mobile radio system for digitally transmitting message information between a plurality of mobile radio stations and a plurality of base stations associated with respective cells of said cellular mobile radio system, 
       
         said message information being in the form of digitally modulated radio signals that are transmitted and received by transmitters and receivers respectively associated with each of said plurality of base and mobile stations, said method comprising the steps of:  
       
       
         transmitting digitally modulated radio signals with identical message information from at least two base stations associated with the same cell, and located at a predetermined distance from one another, to mobile stations within said cell, the digitally modulated radio signals that are transmitted from one of said base stations having certain segments which are transmitted virtually simultaneously and within the same frequency range as digitally modulated radio signals transmitted from the other of said two base stations;  
       
       
         digitally modulating said radio signals at transmission of said message information within modulation time intervals, said modulation the intervals being shorter than the time necessary for radio signals to propagate a distance which corresponds to the greatest transmitting distance between two base stations associated with a cell of said cellular mobile radio system;  
       
       
         reconstructing the digital modulation from corresponding radio signals that are received at a mobile station during a reception time interval, said reception time interval being at least as long as the time required for radio signals to propagate a distance which corresponds to the greatest transmitting distance between said two base stations associated with said cell; and  
       
       
         terminating a radio signal from one of said at least two base stations. 
       
     
     
       15. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations associated with said cells, at least one of said cells having at least two base stations associated therewith and located a distance from one another to transmit respective radio signals into said at least one cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including means for digitally modulating the radio signals with message information, said modulating being carried out with modulation time intervals which are within a time interval related to the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell in said system; and  
       
       
         a plurality of mobile stations each having means for reconstructing the digital modulation of plural corresponding radio signals respectively received over the same frequency range during a reception time interval from said at least two base stations associated with said at least one cell, which reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell, wherein a mobile station is handed off from one of said at least two base stations to another of said at least two base stations. 
       
     
     
       16. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations associated with said cells, at least one of said cells having at least two base stations associated therewith and located a distance from one another to transmit respective radio signals into said at least one cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including means for digitally modulating the radio signals with message information, said modulating being carried out with modulation time intervals which are within a time interval related to the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell in said system; and  
       
       
         a plurality of mobile stations each having means for reconstructing the digital modulation of plural corresponding radio signals respectively received over the same frequency range during a reception time interval from said at least two base stations associated with said at least one cell, which reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell, wherein a radio signal is terminated from one of said at least two base stations. 
       
     
     
       17. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations for transmitting radio signals into a cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including means for digitally modulating the radio signals with message information, said modulating being carried out with modulation time intervals, which are at most a few times greater than a time required for radio signals to propagate a distance corresponding to a diameter of said cell; and  
       
       
         a plurality of mobile stations each having means for reconstructing the digital modulation of plural corresponding radio signals respectively received over the same frequency during a reception time internal from the plurality of base stations, said reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to said diameter of said cell, wherein a mobile station is handed off from one of said plurality of base stations to another of said plurality of base stations. 
       
     
     
       18. A cellular mobile radio system for communication information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations for transmitting radio signals into a cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including means for digitally modulating the radio signals with message information, said modulating being carried out with modulation time intervals which are at most a few times greater than a time required for radio signals to propagate a distance corresponding to a diameter of said cell; and  
       
       
         a plurality of mobile stations each having means for reconstructing the digital modulation of plural corresponding radio signals respectively received over the same frequency during a reception time interval from the plurality of base stations, said reception time interval is at least as long as the tune required for radio signals to propagate a distance corresponding to said diameter of said cell, wherein a radio signal transmitted from one of said plurality of base stations is terminated. 
       
     
     
       19. A cellular mobile radio system for communicating message information and having a plurality of cells, comprising: 
       
         a first base station for transmitting a first signal having message information into a cell,  
       
       
         a second base station for transmitting a second signal having said message information into said cell,  
       
       
         a mobile station in said cell having means for receiving said first and second signals, wherein said first and second signals are received with a propagation delay therebetween,  
       
       
         wherein both of said first and second base stations include means for modulating said first and second signals, respectively, with said message information using a modulation time interval which is no longer than a few multiples of said propagation delay,  
       
       
         wherein said mobile station includes means for reconstructing said first and second signals during a reception time interval which is at least as long as said propagation delay, and  
       
       
         means for handing off said mobile station from one of said base stations to the other base station. 
       
     
     
       20. A cellular mobile radio system for communicating message information and having a plurality of cells, comprising: 
       
         a first base station for transmitting a first signal having message information into a cell,  
       
       
         a second base station for transmitting a second signal having said message information into said cell,  
       
       
         a mobile station in said cell having means for receiving said first and second signals, wherein said first and second signals are received with a propagation delay therebetween,  
       
       
         wherein both of said first and second base stations include means for modulating said first and second signals, respectively, with said message information using a modulation time interval which is no longer than a few multiples of said propagation delay,  
       
       
         wherein said mobile station includes means for reconstructing said first and second signals during a reception time interval which is at least as long as said propagation delay, and  
       
       
         means for terminating a radio signal from one of said base stations. 
       
     
     
       21. A cellular mobile radio system for communicating message information across an area of coverage, comprising: 
       
         a plurality of cells, each of said plurality of cells representing a geographic division of said area of coverage;  
       
       
         a first base station for transmitting a first signal including message information into at least one of said plurality of cells, said first base station including means for modulating a radio carrier with said message information, said message information being represented by a sequence of symbols;  
       
       
         a second base station for transmitting a second signal, including substantially the same message information as transmitted by said first base station, into said at least one of said plurality of cells, said second base station including means for modulating said radio carrier frequency with said substantially the same message information; and  
       
       
         at least one mobile station located within said at least one of said plurality of said cells  
       
       
         wherein said first and said second signals are received by said mobile station with a time shift therebetween wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said first base station and a second propagation delay between said at least one mobile station and said second base station,  
       
       
         said at least one mobile station further including means for recovering said message information from said first and said second signals during a reception time interval which reception time interval is greater than said time shift, wherein a mobile station is handed off from one of said base stations to the other base station. 
       
     
     
       22. A cellular mobile radio system for communicating message information across an area of coverage, comprising: 
       
         a plurality of cells, each of said plurality of cells representing a geographic division of said area of coverage;  
       
       
         a first base station for transmitting a first signal including message information into at least one of said plurality of cells, said first base station including means for modulating a radio carrier with said message information, said message information being represented by a sequence of symbols;  
       
       
         a second base station for transmitting a second signal, including substantially the same message information as transmitted by said first base station, into said at least one of said plurality of cells, said second base station including means for modulating said radio carrier frequency with said substantially the same message information; and  
       
       
         at least one mobile station located within said at least one of said plurality of said cells  
       
       
         wherein said first and said second signals are received by said mobile station with a time shift therebetween wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said first base station and a second propagation delay between said at least one mobile station and said second base station,  
       
       
         said at least one mobile station further including means for recovering said message information from said first and said second signals during a reception time interval which reception time interval is greater than said time shift, wherein a radio signal is terminated from one of said base stations. 
       
     
     
       23. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations associated with said cells, at least one of said cells having at least two base stations associated at a therewith and located a distance from one another to transmit respective radio signals into said at least one cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including a transmitter that digitally modulates the radio signals with message information, said modulation being carried out with modulation time intervals which are within a time interval related to the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell in said system;  
       
       
         a plurality of mobile stations each having a receiver that reconstructs the digital modulation of plural corresponding radio signals respectively received over the same frequency range during a reception time interval from said at least two base stations associated with said at least one cell, which reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell; and  
       
       
         means for handing off a mobile station from one of said at least two base stations to another of said at least two base stations. 
       
     
     
       24. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations associated with said cells, at least one of said cells having at least two base stations associated therewith and located a distance from one another to transmit respective radio signals into said at least one cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including a transmitter that digitally modulates the radio signals with message information, said modulation being carried out with modulation time intervals which are within a time interval related to the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell in said system;  
       
       
         a plurality of mobile stations each having, a receiver that reconstructs the digital modulation of plural corresponding radio signals respectively received over the same frequency range during a reception time interval from said at least two base stations associated with said at least one cell, which reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to the greatest transmitting distance between said at least two base stations associated with said at least one cell; and  
       
       
         means for terminating a radio signal from one of said at least two base stations. 
       
     
     
       25. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations for transmitting radio signals into a cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including a transmitter that digitally modulates the radio signals with message information, said modulation being carried out with modulation time intervals which are at most a few times greater than a time required for radio signals to propagate a distance corresponding to a diameter of said cell;  
       
       
         a plurality of mobile stations each having a receiver that reconstructs the digital modulation of plural corresponding radio signals respectively received over the same frequency during a reception time interval from the plurality of base station, said reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to said diameter of said cell; and  
       
       
         means for handing off a mobile station from one of said plurality of base stations to another of said plurality of base stations. 
       
     
     
       26. A cellular mobile radio system for communicating message information within a geographic area that is divided into communication cells, comprising: 
       
         a plurality of base stations for transmitting radio signals into a cell, which signals are digitally modulated with substantially the same message information and are transmitted at the same frequency and substantially simultaneously with one another,  
       
       
         each base station including a transmitter that digitally modulates the radio signals with message information, said modulation being carried out with modulation time intervals which are at most a few times greater than a time required for radio signals to propagate a distance corresponding to a diameter of said cell;  
       
       
         a plurality of mobile stations each having a receiver that reconstructs the digital modulation of plural corresponding radio signals respectively received over the same frequency during a reception time interval from the plurality of base stations, said reception time interval is at least as long as the time required for radio signals to propagate a distance corresponding to said diameter of said cell;  
       
       
         means for terminating a radio signal from one of said plurality of base stations. 
       
     
     
       27. A cellular mobile radio system for communicating message information and having a plurality of cells, comprising: 
       
         a first base station for transmitting a first signal having message information into a cell,  
       
       
         a second base station for transmitting a second signal having said message information into said cell,  
       
       
         a mobile station in said cell having a receiver that receives said first and second signals, wherein said first and second signals are received with a propagation delay therebetween,  
       
       
         wherein both of said first and second base stations include a transmitter that modulates said first and second signals, respectively, with said message information using a modulation time interval which is no longer than a few multiples of said propagation delay,  
       
       
         wherein said mobile station receiver reconstructs said first and second signals during a reception time interval which is at least as long as said propagation delay, and  
       
       
         means for handing off a mobile station from one of said base stations to the other of said base stations. 
       
     
     
       28. A cellular mobile radio system for communicating message information and having a plurality of cells, comprising: 
       
         a first base station for transmitting a first signal having message information into a cell,  
       
       
         a second base station for transmitting a second signal having said message information into said cell,  
       
       
         a mobile station in said cell having a receiver that receives said first and second signals, wherein said first and second signals are received with a propagation delay therebetween,  
       
       
         wherein both of said first and second base stations include a transmitter that modulates said first and second signals, respectively, with said message information using a modulation time interval which is no longer than few multiples of said propagation delay,  
       
       
         wherein said mobile station receiver reconstructs said first and second signals during a reception time interval which is at least as long as said propagation delay, and  
       
       
         means for terminating a radio signal from one of said base stations. 
       
     
     
       29. A cellular mobile radio system for communicating message information across an area of coverage, comprising: 
       
         a plurality of cells, each of said plurality of cells representing a geographic division of said area of coverage;  
       
       
         a first base station for transmitting a first signal including message information into at least one of said plurality of cells, said first base station including a transmitter that modulates a radio carrier with said message information, said message information being represented by a sequence of symbols;  
       
       
         a second base station for transmitting a second signal, including substantially the same message information as transmitted by said first base station, into said at least one of said plurality of cells, said second base station including a transmitter that modulates said radio carrier frequency with said substantially the same message information;  
       
       
         at least one mobile station located within said at least one of said plurality of said cells  
       
       
         wherein said first and said second signals are received by said mobile station with a time shift therebetween wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said first base station and a second propagation delay between said at least one mobile station and said second base station,  
       
       
         said at least one mobile station further including a receiver that recovers said message information from said first and said second signals during a reception time interval which reception time interval is greater than said time shift, and  
       
       
         means for handing off a mobile station from one of said base stations to the other of said base stations. 
       
     
     
       30. A cellular mobile radio system for communicating message information across an area of coverage, comprising: 
       
         a plurality of cells each of said plurality of cells representing a geographic division of said area of coverage;  
       
       
         a first base station for transmitting a first signal including message information into at least one of said plurality of cells, said first base station including a transmitter that modulates a radio carrier with said message information, said message information being represented by a sequence of symbols;  
       
       
         a second base station for transmitting a second signal, including substantially the same message information as transmitted by said first base station, into said at least one of said plurality of cells, said second base station including a transmitter that modulates said radio carrier frequency with said substantially the same message information;  
       
       
         at least one mobile station located within said at least one of said plurality of said cells  
       
       
         wherein said first and said second signals are received by said mobile station with a time shift therebetween wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said first base station and a second and propagation delay between said at least one mobile station and said second base station,  
       
       
         said at least one mobile station further including a receiver that recovers said message information from said first and said second signals during a reception time interval which reception time interval is greater than said time shift, and  
       
       
         means for terminating radio signal from one of said base stations. 
       
     
     
       31. A cellular mobile radio system for communicating message information and having a plurality of cells, comprising: 
       
         a first base station for transmitting a first signal having message information into a cell,  
       
       
         a second base station for transmitting a second signal having said message information into said cell,  
       
       
         a mobile station in said cell having a receiver that receives said first and second signals, wherein said first and second signals are received with a propagation delay therebetween,  
       
       
         wherein both of said first and second base stations include a transmitter that modulates said first and second signals, respectively, with said message information using a modulation time interval which is no longer than a few multiples of said propagation delay,  
       
       
         wherein said mobile station receiver reconstructs said message information from said first and second signals received during a reception time interval which is at least as long as said propagation delay, and  
       
       
         wherein said first base station terminates transmission of said first signal while said second base station continues to transmit said second signal to thereby handoff said mobile station from said first base station to said second base station. 
       
     
     
       32. A cellular mobile radio system for servicing calls to and from a plurality of mobile stations located within an area of coverage that is divided into a plurality of cells, said system providing for handover of a call in progress to one of said mobile stations as said mobile station moves between adjacent cells, said system comprising: 
       
         a first base station for transmitting a first signal including message information into it least one of said plurality of cells, said message information transmitted as a sequence of symbols representing a call to one of said mobile stations;  
       
       
         a second base station for transmitting a second signal, including substantially the same message information as transmitted by said first base station, into said at least one of said plurality of cells, said second base station commencing the simultaneous transmission of substantially the same message information as said first base station prior to said handover of said call from said first base station to said second base station; and  
       
       
         at least one mobile station located within said at least one of said plurality of said cells wherein said first and said second signals are received by said mobile station with a time shift therebetween wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said second base station, said at least one mobile station further including a receiver that recovers said message information from a combination of said first and said second signals received during a reception time interval which reception time interval is greater than said time shift, said system performing the handover of said call in progress by terminating the transmission of said first signal when said mobile station moves from said at least one of said plurality of cells into an adjacent cell. 
       
     
     
       33. A cellular mobile radio system for servicing calls to and from a plurality of mobile stations located within an area of coverage that is divided into a plurality of cells, said system providing for handover of a call in progress to one of said plurality of mobile stations as said one of said plurality of mobile stations moves between adjacent cells, said system comprising: 
       
         a plurality of base stations associated with said plurality of cells for transmitting radio signals into said cells, each base station including a transmitter that is adapted to digitally modulate the radio signals with message information, one of said radio signals being modulated with message information representing said call in progress to said one of said plurality of mobile stations, said modulation being carried out with modulation time intervals which are no longer than a few multiples of a propagation delay associated with reception of said radio signals; and  
       
       
         each of said plurality of mobile stations having a receiver that reconstructs the digital modulation of plural corresponding radio signals respectively received during a reception time interval from the plurality of base stations, said reception time interval is at least as long as said propagation delay, said system performing a handover of said call in progress from a first one of said plurality of base stations to one of said plurality of mobile stations in one of said plurality of cells by commencing the simultaneous transmission from a second one of said plurality of base stations in an adjacent cell of substantially the same message information as transmitted by said first base station and terminating the transmission of said message information from said first base station when said mobile station has moved into said adjacent cell. 
       
     
     
       34. A method for handing off a call between a mobile station and a first base station to a second base station in a cellular mobile radio system comprising the steps of: 
       
         providing a plurality of cells, each of said plurality of cells representing a geographic division of said area of coverage;  
       
       
         transmitting, from said first base station, a first signal including message information into at least one of said plurality of cells;  
       
       
         transmitting, from said second base station, a second signal, including substantially the same message information as said first signal, into said at least one of said plurality of cells;  
       
       
         receiving, at said mobile station, said first and second signals with a time shift therebetween, wherein said time shift arises from a difference in a first radio propagation delay between said at least one mobile station and said first base station and a second propagation delay between said at least one mobile station and said second base station;  
       
       
         combining, in said mobile station, information from said first and said second signals received during a reception time interval which reception time interval is greater than said time shift; and  
       
       
         terminating, at said first base station, transmission of said first signal, thereby handing off said call to said second base station.