System, method and apparatus for transmit diversity control based on variations in propagation path

Abstract

A method and apparatus for applications of identification of variations of propagation path to transmit diversity control. Transmit diversity parameters may be modified according to detected dynamics, which may, for example, be related to changes in actual propagation and network conditions. Such dynamics may be referred to as mobility parameters. Mobility parameters may apply to variability in a propagation path due to any conditions. Determination of a mobility parameter may be conducted using one or more of multiple parameters available to the mobile terminal. Such feedback information indication, which is related to the propagation path conditions, may be provided to the apparatus, which would attempt to find a more desired mode of operation, which may lead to reduction in power and the improvement of the quality of transmission.

1 . A transmit diversity communication method comprising:
 transmitting from first and second antennas of a first device a first transmit diversity signal, wherein said first and second antennas transmit signals differing by a first value of a diversity parameter;   calculating at said first device a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between said first device and a second device;   calculating based at least on said mobility parameter value and on said first diversity parameter value a second diversity parameter value; and   transmitting from said first and second antennas of said first device a second transmit diversity signal, wherein signals transmitted on said first and second antennas differ by said second value of the diversity parameter.   
     
     
         2 . The transmit diversity method of  claim 1 , wherein said diversity parameter relates to a ratio between a transmission power of said signal transmitted on the first antenna and a transmission power of said signal transmitted by the second antenna. 
     
     
         3 . The transmit diversity method of  claim 1 , wherein said diversity parameter relates to a difference between a phase of said signal transmitted on the first antenna and a phase of said signal transmitted by the second antenna. 
     
     
         4 . The transmit diversity method of  claim 1 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         5 . The transmit diversity method of  claim 1 , wherein said second value of the diversity parameter is further based on at least one previous value of said diversity parameter. 
     
     
         6 . The transmit diversity method of  claim 5 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         7 . A transmit diversity communication apparatus comprising:
 first and second antennas for transmitting respective signals;   a signal modifier to receive a signal, to modify said signal by a diversity parameter, and to send to said first and second antennas first and second respective signals differing with respect to a first value of the diversity parameter; and   a processor to calculate a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between the communication apparatus and a second communication device, and further to calculate based at least on said mobility parameter value and on said first value of said diversity parameter a second value of said diversity parameter,   wherein said signal modifier is further to send to said first and second antennas first and second respective signals differing with respect to said second value of the diversity parameter.   
     
     
         8 . The transmit diversity communication apparatus of  claim 7 , wherein said diversity parameter relates to a ratio between a transmission power of said signal transmitted on the first antenna and a transmission power of said signal transmitted by the second antenna. 
     
     
         9 . The transmit diversity communication apparatus of  claim 7 , wherein said diversity parameter relates to a difference between a phase of said signal transmitted on the first antenna and a phase of said signal transmitted by the second antenna. 
     
     
         10 . The transmit diversity communication apparatus of  claim 7 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         11 . The transmit diversity communication apparatus of  claim 7 , wherein said second value of the diversity parameter is further based on at least one previous value of said diversity parameter. 
     
     
         12 . The transmit diversity communication apparatus of  claim 11 , wherein said second value of the diversity parameter is farther based on at least one previous value of said mobility parameter. 
     
     
         13 . A transmit diversity communication method comprising:
 transmitting from first and second antennas of said first device a first transmit diversity signal, wherein said first and second antennas transmit signals differing by a first value of a diversity parameter;   calculating at said first device a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between said first device and a second device;   if the value of said mobility parameter satisfies a high mobility condition, then using a high mobility algorithm to calculate based at least on said mobility parameter value and on said first diversity parameter value a second diversity parameter value;   if the value of said mobility parameter satisfies a low mobility condition, then using a low mobility algorithm to calculate based at least on said mobility parameter value and on said first diversity parameter value a second diversity parameter value; and   transmitting from said first and second antennas of said first device a second transmit diversity signal, wherein signals transmitted on said first and second antennas differ by said second value of the diversity parameter.   
     
     
         14 . The transmit diversity method of  claim 13 , wherein said diversity parameter relates to a ratio between a transmission power of said signal transmitted on the first antenna and a transmission power of said signal transmitted by the second antenna. 
     
     
         15 . The transmit diversity method of  claim 13 , wherein said diversity parameter relates to a difference between a phase of said signal transmitted on the first antenna and a phase of said signal transmitted by the second antenna. 
     
     
         16 . The transmit diversity method of  claim 13 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         17 . The transmit diversity method of  claim 13 , wherein said second value of the diversity parameter is further based on at least one previous value of said diversity parameter. 
     
     
         18 . The transmit diversity method of  claim 17 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         19 . A transmit diversity communication apparatus comprising:
 first and second antennas;   a signal modifier to receive a signal, to modify said signal by a diversity parameter, and to send to said first and second antennas a respective plurality of signals differing with respect to a first value of the diversity parameter; and   a processor to calculate a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between the communication apparatus and a second device,   wherein the processor is adapted to use a high mobility algorithm to calculate a second diversity parameter value based at least on said mobility parameter value and on said first diversity parameter value if the value of said mobility parameter satisfies a high mobility condition,   wherein the processor is further adapted to use a low mobility algorithm to calculate a second diversity parameter value based at least on said mobility parameter value and on said first diversity parameter value if the value of said mobility parameter satisfies a low mobility condition, and   wherein said signal modifier is further to send to said first and second antennas a respective plurality of signals differing with respect to said second value of the diversity parameter.   
     
     
         20 . The transmit diversity communication apparatus of  claim 19 , wherein said diversity parameter relates to a ratio between a transmission power of said signal transmitted on the first antenna and a transmission power of said signal transmitted by the second antenna. 
     
     
         21 . The transmit diversity communication apparatus of  claim 19 , wherein said diversity parameter relates to a difference between a phase of said signal transmitted on the first antenna and a phase of said signal transmitted by the second antenna. 
     
     
         22 . The transmit diversity communication apparatus of  claim 19 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         23 . The transmit diversity communication apparatus of  claim 19 , wherein said second value of the diversity parameter is further based on at least one previous value of said diversity parameter. 
     
     
         24 . The transmit diversity communication apparatus of  claim 23 , wherein said second value of the diversity parameter is further based on at least one previous value of said mobility parameter. 
     
     
         25 . An antenna selection method comprising:
 transmitting alternatingly from a first antenna and a second antenna of a first device, wherein the ratio of transmission time of one of said antennas to a total transmission time is based on a duty cycle value;   calculating at said first device a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between said first device and a second device;   modifying said duty cycle value based at least on said at least one mobility parameter; and   transmitting alternatingly from said first antenna and said second antenna of the first device, wherein the ratio of transmission time of said one of said antennas to a total transmission time is based on the modified duty cycle value.   
     
     
         26 . The antenna selection method of  claim 25 , wherein modifying said duty cycle value comprises changing primary antenna from one of said antennas to the other of said antennas based on said calculated mobility parameter, wherein the antenna having a greater transmission duty cycle is the primary antenna. 
     
     
         27 . The antenna selection method of  claim 26 , wherein modifying said duty cycle value comprises changing primary antenna from one of said antennas to the other of said antennas if said at least one calculated mobility parameter value indicates that the change in propagation results in improved transmission by a secondary antenna with respect to said primary antenna, wherein the antenna having a lesser transmission duty cycle is the secondary antenna. 
     
     
         28 . The antenna selection method of  claim 27 , wherein changing primary antenna comprises changing primary antenna from one of said antennas to the other of said antennas if said at least one calculated mobility parameter value indicates improved transmission by said secondary antenna with respect to said primary antenna by at least a power gain hysteresis threshold value. 
     
     
         29 . The antenna selection method of  claim 27 , wherein changing primary antenna comprises changing primary antenna from one of said antennas to the other of said antennas if said at least one calculated mobility parameter value indicates improved transmission by said secondary antenna with respect to said primary antenna over a plurality of cycles of alternating transmissions from said first and second antennas. 
     
     
         30 . An antenna selection communication apparatus comprising:
 first and second antennas;   a signal modifier to alternatingly send respective signals to said first and second antennas for transmission, wherein the ratio of transmission time of said first antenna to a total transmission time is based on a duty cycle value; and   a processor to calculate a value of at least one mobility parameter, said mobility parameter indicating a change in propagation of a signal transmitted between the communication apparatus and a second device,   wherein the processor is adapted to calculate a modified duty cycle value based at least on said at least one mobility parameter, and   wherein said signal modifier is further to send said input signal to said first and second antennas for transmission, wherein the ratio of transmission time of said first antenna to a total transmission time is based on the modified duty cycle value.   
     
     
         31 . The antenna selection communication apparatus of  claim 30 , wherein said processor is to calculate said modified duty cycle value so as to change primary antenna from one of said antennas to the other of said antennas based on said calculated mobility parameter, wherein the antenna having a greater transmission duty cycle is the primary antenna. 
     
     
         32 . The antenna selection communication apparatus of  claim 31 , wherein said processor is to calculate said modified duty cycle so as to change primary antenna from one of said antennas to the other of said antennas if said at least one calculated mobility parameter value indicates that the change in propagation results in improved transmission by a secondary antenna with respect to said primary antenna, wherein the antenna having a lesser transmission duty cycle is the secondary antenna. 
     
     
         33 . The antenna selection method of  claim 32 , wherein said processor is to calculate said modified duty cycle so as to change primary antenna if said at least one calculated mobility parameter value indicates improved transmission by said secondary antenna with respect to said primary antenna by at least a power gain hysteresis threshold value. 
     
     
         34 . The antenna selection method of  claim 32 , wherein said processor is to calculate said modified duty cycle so as to change primary antenna if said at least one calculated mobility parameter value indicates improved transmission by said secondary antenna with respect to said primary antenna over a plurality of cycles of alternating transmissions from said first and second antennas.