Cellular radiotelephone signal with additional channel assigned to downlink, corresponding method, system, mobile and base station

Abstract

The invention concerns a cellular radio telephone signal comprising a symmetrical two-way main channel, including a main uplink and a main downlink, in particular transmitting low or medium speed data and signalling and control data, and comprising at least one additional channel solely assigned to the downlink, transmitting in particular, high speed data transmission. At one given time, all or part of said supplementary channel transmission capacity can be dynamically allocated to a particular mobile station. Information for retrieving data intended for a particular mobile station and carried by said supplementary channel can be transmitted among said main downlink signalling and control data.

1 . A cellular radiotelephone signal, of the type including a main symmetrical bidirectional channel, including a main uplink and a main downlink, providing in particular low or medium speed transmission of signalling and control data and information, 
 characterised in that it includes at least one additional channel solely assigned to downlink, providing in particular high speed data transmission.    
   
   
       2 . A cellular radiotelephone signal according to  claim 1 , characterised in that, at a given moment, all or part of the transmission capacity of said additional channel is allocated dynamically to a particular mobile station.  
   
   
       3 . A cellular radiotelephone signal according to  claim 2 , characterised in that information allowing the retrieval of data intended for a particular mobile station and carried by said additional channel is transmitted among said signalling and control information of said main downlink.  
   
   
       4 . A cellular radiotelephone signal according to any one of  claims 1  to  3 , characterised in that said main channel and said additional channel have synchronous frame structures.  
   
   
       5 . A cellular radiotelephone signal according to any one of  claims 1  to  4 , characterised in that said additional channel also provides for transmission of signalling and control information.  
   
   
       6 . A cellular radiotelephone signal according to  claim 5 , characterised in that said additional channel provides at least for transmission of signalling and control information intended for mobile station(s) in the method of transmitting data intended for said mobile station, on said additional channel.  
   
   
       7 . A cellular radiotelephone signal according to  claim 6 , characterised in that, when said additional channel carries high speed data intended for said mobile station, said signalling and control information intended for a mobile station is duplicated or switched from said main downlink onto said additional channel.  
   
   
       8 . A cellular radiotelephone signal according to any one of  claims 1  to  7 , characterised in that said main channel implements a spread spectrum access technology (CDMA).  
   
   
       9  A cellular radiotelephone signal according to any one of  claims 1  to  8 , characterised in that said additional channel implements a multi-carrier technology providing distribution of data in the time/frequency space.  
   
   
       10 . A cellular radiotelephone signal according to  claim 9 , characterised in that said additional channel has a complex envelope responding to the following equation:  
     
       
         
           
             
               x 
               ⁡ 
               
                 ( 
                 t 
                 ) 
               
             
             = 
             
               
                 ∑ 
                 
                   m 
                   , 
                   n 
                 
               
               ⁢ 
               
                 
                   a 
                   
                     m 
                     , 
                     n 
                   
                 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   i 
                   
                     m 
                     + 
                     n 
                   
                 
                 ⁢ 
                 
                   ?? 
                   ⁡ 
                   
                     ( 
                     
                       t 
                       - 
                       
                         n 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         T 
                       
                     
                     ) 
                   
                 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   ⅇ 
                   
                     ⅈ 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     π 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     m 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       t 
                       / 
                       T 
                     
                   
                 
               
             
           
         
       
     
     where: 
 .m is an integer representing the frequential dimension;  
 .n is an integer representing the temporal dimension;  
 .t represents time;  
 .T is the time symbol;  
 .a m,n  is a real digital coefficient chosen from a pre-set alphabet;  
 .ℑ is the prototype IOTA function (as defined in FR-95 05455).  
 
   
   
       11 . A cellular radiotelephone signal according to any one of claims  9  and  10 , characterised in that the transmission capacity of said additional channel is allocated to a given mobile station, dynamically, in the form of at least one block defined in the time/frequency space.  
   
   
       12 . A cellular radiotelephone signal according to  claim 11 , characterised in that said signalling and control information of said main downlink includes retrieval information of said blocks in the time/frequency space.  
   
   
       13 . A cellular radiotelephone signal according to any one of claims  11  and  13 , characterised in that at least some of said blocks carry temporal and/or frequential synchronisation references.  
   
   
       14 . A cellular radiotelephone system of the type implementing a main symmetrical bidirectional channel, including a main uplink and a main downlink, providing in particular low or medium speed transmission of signalling and control data and information, characterised in that it also implements at least one additional channel solely assigned to the downlink, providing in particular high speed data transmission.  
   
   
       15 . A cellular radiotelephone method of the type implementing a main symmetrical bidirectional channel, including a main uplink and a main downlink, providing in particular low or medium speed transmission of signalling and control data and information, 
 characterised in that it also implements at least one additional channel solely assigned to the downlink, providing in particular high speed data transmission.    
   
   
       16 . A mobile station of a cellular radiotelephone system, including emission means of main uplink and reception means of a main downlink, said uplinks and downlinks forming a main symmetrical bidirectional channel providing in particular low or medium speed transmission of signalling and control data and information, 
 characterised in that it also includes reception means of at least one additional channel solely assigned to the downlink, providing in particular high speed data transmission.    
   
   
       17 . A mobile station of a cellular radiotelephone system according to  claim 16 , characterised in that it includes single synchronisation means implementing an analysis of said main channel and delivering synchronisation information to methoding means of said main channel and to methoding means of said additional channel.  
   
   
       18 . A mobile station of a cellular radiotelephone system according to any one of claims  16  and  17 , characterised in that it includes a single reception link including particularly transposition means onto an intermediate frequency of a received signal and demodulation means of the transposed signal, said received signal being able to be selectively said main downlink or said additional channel.  
   
   
       19 . A mobile station of a cellular radiotelephone system according to any one of  claims 16  to  18 , characterised in that it includes recovery means of said signalling and control information selectively on said main downlink or on said additional channel.  
   
   
       20 . A base station of a cellular radiotelephone system, of the type including reception means of a main uplink and emission means of a main downlink, said uplinks and downlinks forming a main symmetrical bidirectional channel providing in particular low or medium speed transmission of signalling and control data and information, 
 characterised in that it also includes emission means of at least one additional channel solely assigned to the downlink, providing in particular high speed data transmission.    
   
   
       21 . A base station of a cellular radiotelephone system according to  claim 20 , characterised in that it includes transmission means of signalling and control information intended for a given mobile station on said additional channel, when the latter carries high speed data intended for said mobile station.