Satellite broadcasting system

Abstract

In a broadcasting receiver, to quickly switch channels of the received multiplexed broadcasting signals at a high response speed to improve the convenience for a viewer, when broadcasting signals of a plurality of channels are to be code-division-multiplexed and broadcasted from a ground broadcasting station (BC 1, BC 2 ) to a broadcasting receiver (MS) in a service area via a geostationary satellite (SAT), the broadcasting signals are multiplexed and transmitted after matching the spreading code phase between the channels in the ground broadcasting station (BC 1, BC 2 ). Alternatively, the spreading code phase difference between the channels of a CDM broadcasting signal arriving from the ground broadcasting station (BC 1, BC 2 ) is detected in the geostationary satellite (SAT), and the broadcasting signal is transmitted to the broadcasting receiver (MS) after matching the spreading code phase between the channels on the basis of the detection result.

1 . A radio receiver (MS) carried by a mobile (MS) and used in a radio communication system for radio-transmitting a transmission signal modulated by a predetermined modulation scheme for multipath transmission for which both a direct wave and an indirect wave are used, said apparatus (MS) comprising: signal synthesis means ( 213 ) for synthesizing signals obtained by a plurality of antennas ( 211 ,  212 ) spaced apart from each other; and 
 reception means ( 214 ) for receiving a synthesis signal obtained by said signal synthesis means and performing predetermined multipath reception processing.    
     
     
         2 . A radio receiver according to  claim 1 , wherein two of the plurality of antennas ( 211 ,  212 ) are arranged on the mobile while being offset from each other both in a moving direction of the mobile carrying the antennas and in a direction perpendicular to the moving direction.  
     
     
         3 . A radio receiver according to  claim 1 , wherein two antennas ( 211 ,  212 ) provided on the mobile while being offset from each other both in a moving direction of the mobile carrying the antennas and in a direction perpendicular to the moving direction are respectively arranged near two points on a contour of the mobile where a linear distance between the two antennas is maximized.  
     
     
         4 . A radio receiver (MS) used in a radio communication system for radio-transmitting a predetermined transmission signal and carried by a mobile (MS), said apparatus (MS) comprising: 
 reception means ( 214 ) for demodulating transmission data from the radio-transmitted transmission signal;    storage means ( 225 ) for storing the transmission data obtained by said reception means at least for a predetermined period;    hit detection means ( 226 ) for detecting a hit generated in the transmission signal received by said reception means; and    compensation means ( 227 ) for compensating transmission data corresponding to a transmission signal portion where the hit is detected by said hit detection means, on the basis of the transmission data stored in said storage means.    
     
     
         5 . A radio broadcasting system for radio-broadcasting a predetermined transmission signal from a radio broadcasting apparatus (BC 1 , BC 2 ) to a radio receiver (MS), said system comprising: 
 reception means ( 228 ), arranged in the radio receiver, for demodulating transmission data from the radio-broadcasted transmission signal;    delay means ( 229 ), arranged in the radio receiver, for delaying the transmission data obtained by said reception means at least for a predetermined period;    hit detection means ( 231 ), arranged in the radio receiver, for detecting a hit generated in-the transmission signal received by said reception means;    retransmission request means ( 232 ), arranged in the radio receiver, for requesting the radio broadcasting apparatus to retransmit a transmission signal corresponding to a portion where the hit is detected by said hit detection means;    retransmission means ( 237 ), arranged in the radio broadcasting apparatus, for transmitting the transmission signal corresponding to the requested portion using a predetermined retransmission channel in response to the retransmission request from said retransmission request means; and    compensation means ( 230 ), arranged in the radio receiver, for compensating, in the transmission data delayed by said delay means, transmission data corresponding to the transmission signal portion where the hit is detected by said hit detection means, using transmission data demodulated, by said reception means, from the transmission signal transmitted from said retransmission means in response to the request from said retransmission request means and arriving through the retransmission channel.    
     
     
         6 . A radio receiver (MS) carried by a mobile (MS) and used in a radio broadcasting system for radio-broadcasting a predetermined transmission signal from a radio broadcasting apparatus (BC 1 , BC 2 ) to the radio receiver (MS), said apparatus.(MS) comprising: 
 reception means ( 228 ) for demodulating transmission data from the radio-broadcasted transmission signal;    delay means ( 229 ) for delaying the transmission data obtained by said reception means at least for a predetermined period;    hit detection means ( 231 ) for detecting a hit generated in the transmission signal received by said reception means;    retransmission request means ( 232 ) for requesting the radio broadcasting apparatus to retransmit a transmission signal corresponding to a portion where the hit is detected by said hit detection means; and    compensation means ( 230 ) for compensating, in the transmission data delayed by said delay means, transmission data corresponding to the transmission signal portion where the hit is detected by said hit detection means, using transmission data demodulated, by said reception means, from the transmission signal transmitted from the radio broadcasting apparatus in response to the request from said retransmission request means and arriving through a predetermined retransmission channel.    
     
     
         7 . A radio broadcasting apparatus (BC 1 , BC 2 ) used in a radio broadcasting system for radio-broadcasting a predetermined transmission signal from the radio broadcasting apparatus (BC 1 , BC 2 ) to a radio receiver (MS), said apparatus (BC 1 , BC 2 ) comprising: 
 means ( 240 ) for receiving a retransmission request from the radio receiver; and     retransmission means ( 237 ) for transmitting a transmission signal of a requested portion using a predetermined retransmission channel in response to the request.