Wireless communication system, baseband processing device, and wireless device

Abstract

A wireless communication system includes a baseband processing device configured to transmit a data signal via an optical transmission line, and a wireless device configured to receive the data signal via the optical transmission line and carry out wireless transmission of an output signal obtained by amplifying the data signal, wherein the wireless device is configured to amplify the data signal to generate the output signal, generate a feedback signal according to the output signal, and transmit the feedback signal to the baseband processing device via the optical transmission line, and wherein the baseband processing device is configured to acquire the feedback signal from the wireless device, and execute first processing of multiplying the data signal by a distortion compensation coefficient corresponding to an inverse characteristic of distortion in the radio frequency circuit based on the feedback signal.

What is claimed is: 
     
         1 . A wireless communication system comprising:
 a baseband processing device configured to transmit a data signal via an optical transmission line; and   a wireless device configured to receive the data signal via the optical transmission line and carry out wireless transmission of an output signal obtained by amplifying the data signal,   wherein the wireless device includes
 a radio frequency circuit configured to amplify the data signal to generate the output signal, 
 a first memory, and 
 a first processor coupled to the first memory and configured to
 generate a feedback signal according to the output signal generated by the radio frequency circuit, and 
 transmit the feedback signal to the baseband processing device via the optical transmission line, and 
 
   wherein the baseband processing device includes
 a second memory, and 
 a second processor coupled to the second memory and configured to
 acquire the feedback signal from the wireless device, and 
 execute first processing of multiplying the data signal by a distortion compensation coefficient corresponding to an inverse characteristic of distortion in the radio frequency circuit based on the feedback signal. 
 
   
     
     
         2 . The wireless communication system according to  claim 1 , wherein
 the second processor is configured to
 receive a first known signal transmitted from the wireless device via the optical transmission line, and 
 stop processing of updating the distortion compensation coefficient when an error is detected in the first known signal. 
   
     
     
         3 . The wireless communication system according to  claim 1 , wherein
 the second processor is configured to
 transmit a second known signal to the wireless device via the optical transmission line, 
 calculate round-trip time on a basis of transmission timing of the second known signal and reception timing of a return signal transmitted from the wireless device in response to the second known signal, and 
 correct delay time in the first processing on a basis of the round-trip time. 
   
     
     
         4 . The wireless communication system according to  claim 1 , wherein
 the first processor is configured to
 execute first count processing, and 
   the second processor is configured to
 execute second count processing, 
 output a frame timing signal in the baseband processing device based on the second count processing, and 
 correct the second count processing based on the first count processing. 
   
     
     
         5 . The wireless communication system according to  claim 4 , wherein
 the second processor is configured to transmit a count value in the second count processing to the wireless device.   
     
     
         6 . A baseband processing device configured to transmit a data signal to a wireless device via an optical transmission line and receive a feedback signal according to an output signal generated through amplification of the data signal in the wireless device from the wireless device via the optical transmission line, the baseband processing device comprising:
 a memory; and   a processor coupled to the memory and configured to
 receive the feedback signal from the wireless device, and 
 execute first processing of multiplying the data signal by a distortion compensation coefficient corresponding to an inverse characteristic of distortion in a wireless frequency circuit on a basis of the feedback signal. 
   
     
     
         7 . The baseband processing device according to  claim 6 , wherein
 the processor is configured to
 receive a first known signal transmitted from the wireless device via the optical transmission line, and 
 stop processing of updating the distortion compensation coefficient when an error is detected in the first known signal. 
   
     
     
         8 . The baseband processing device according to  claim 6 , wherein
 the processor is configured to
 transmit a second known signal to the wireless device via the optical transmission line, 
 calculate round-trip time on a basis of transmission timing of the second known signal and reception timing of a return signal transmitted from the wireless device in response to the second known signal, and 
 correct delay time in the first processing on a basis of the round-trip time. 
   
     
     
         9 . The baseband processing device according to  claim 6 , wherein
 the wireless device execute first count processing, and   the processor is configured to
 execute second count processing, 
 output a frame timing signal in the baseband processing device based on the second count processing, and 
 correct the second count processing based on the first count processing. 
   
     
     
         10 . The baseband processing device according to  claim 9 , wherein
 the processor is configured to transmit a count value in the second count processing to the wireless device.   
     
     
         11 . A wireless device configured to receive a data signal from a baseband processing device via an optical transmission line and carry out wireless transmission of an output signal obtained by amplifying the data signal, the wireless device comprising:
 a radio frequency circuit configured to amplify the data signal to generate the output signal;   a memory; and   a processor coupled to the memory and configured to
 generate a feedback signal according to the output signal generated by the radio frequency circuit, and 
 transmit the feedback signal to the baseband processing device via the optical transmission line. 
   
     
     
         12 . The wireless device according to  claim 11 , wherein
 the baseband processing device execute first count processing, and   the processor is configured to
 execute second count processing, 
 output a frame timing signal in the wireless device based on the second count processing, and 
 correct the second count processing based on the first count processing. 
   
     
     
         13 . The wireless device according to  claim 11 , wherein
 the processor is configured to
 execute count processing, 
 output a frame timing signal in the wireless device based on the second count processing, and 
 transmit a counting value of the count processing to the baseband processing device via the optical transmission line.