Radio communication system using TDD scheme
First Claim
1. A radio communication system wherein, the radio communication is conducted in TDD scheme via a radio channel between a first radio station and a second radio station, at least, either of which is movable, comprising:
- said first radio station including;
error correction encoding means for encoding a series of input digital information by using a first error correction code having a predetermined error correction capability;
erasure correction encoding means for encoding the series of digital information encoded by said error correction encoding means by using a second error correction code having a predetermined erasure correction capability; and
transmitting means for transmitting the series of digital information coded by said encoding means over said radio channel within a predetermined transmission period, after modulating it with a predetermined digital modulation scheme; and
said second radio station including;
receiving means for outputting a demodulated signal by digitally demodulating it, after receiving the radio signal coming from within a predetermined receiving period via said radio channel;
erasure correction decoding means for restoring erasure data by performing an erasure correction decoding process on the demodulated signal outputted from said receiving means, on the basis of said second error correction code; and
error correction decoding means for performing an error correction process on the demodulated signal undergone the erasure correction decoding process by said erasure correction decoding means by using said first error correction code,said error correction encoding means performing the error correction encoding process on the series of input digital information by using a convolutional code,said erasure correction encoding means performing the erasure correction encoding process on the series of digital information undergone the error correction encoding process performed by said error correction encoding means, by using a block code,said erasure correction decoding means performing the erasure correction process on the demodulated signal on the basis of said block code, andsaid error correction decoding means performing the error correction process on the demodulated signal undergone the erasure correction process performed by said erasure correction decoding means, by using a viterbi decoder.
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Accused Products
Abstract
The system in this invention is provided with a ground radio channel for performing the radio communication by directly connecting between base stations and mobile stations, and a satellite radio channel for performing the radio communication by connecting the base stations and mobile stations via communication satellite. When a mobile stations performs communication, which ever of said ground radio channel or satellite radio channel is selected. Moreover, when a ground radio channel is selected in accordance with the selection of this radio channel, the block code prioritizing the error correction capability is set to the channel codec so as to perform the correction is encoding and decoding process prioritizing the error correction capability. As contrast to that, when a satellite radio channel is selected, the block code prioritizing the erasure code correction capability is set to the channel codec so as to perform the error correction encoding and decoding process prioritizing the erasure code correction.
41 Citations
12 Claims
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1. A radio communication system wherein, the radio communication is conducted in TDD scheme via a radio channel between a first radio station and a second radio station, at least, either of which is movable, comprising:
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said first radio station including; error correction encoding means for encoding a series of input digital information by using a first error correction code having a predetermined error correction capability; erasure correction encoding means for encoding the series of digital information encoded by said error correction encoding means by using a second error correction code having a predetermined erasure correction capability; and transmitting means for transmitting the series of digital information coded by said encoding means over said radio channel within a predetermined transmission period, after modulating it with a predetermined digital modulation scheme; and said second radio station including; receiving means for outputting a demodulated signal by digitally demodulating it, after receiving the radio signal coming from within a predetermined receiving period via said radio channel; erasure correction decoding means for restoring erasure data by performing an erasure correction decoding process on the demodulated signal outputted from said receiving means, on the basis of said second error correction code; and error correction decoding means for performing an error correction process on the demodulated signal undergone the erasure correction decoding process by said erasure correction decoding means by using said first error correction code, said error correction encoding means performing the error correction encoding process on the series of input digital information by using a convolutional code, said erasure correction encoding means performing the erasure correction encoding process on the series of digital information undergone the error correction encoding process performed by said error correction encoding means, by using a block code, said erasure correction decoding means performing the erasure correction process on the demodulated signal on the basis of said block code, and said error correction decoding means performing the error correction process on the demodulated signal undergone the erasure correction process performed by said erasure correction decoding means, by using a viterbi decoder.
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2. A radio communication apparatus for performing a radio communication in TDD scheme via a radio channel, comprising:
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encoding means including; error correction encoding means for encoding a series of input digital information by using a first error correction code having a predetermined error correction capability; and erasure correction encoding means for encoding the series of digital information having been encoded by said error correction encoding means by using a second error correction code having a predetermined erasure correction capability; transmitting means for transmitting the series of digital information having been encoded by said encoding means over said radio channel within a predetermined transmitting period, after modulating it with a predetermined digital modulation scheme; receiving means for outputting a demodulated signal by digital demodulation after receiving the radio signal coming from within a predetermined receiving period via said radio channel; and decoding means including; erasure code correction decoding means for restoring erasure data by performing an erasure correction decoding process on the demodulated signal outputted from said receiving means, on the basis of said second error correction code; and error correction decoding means for performing an error correction process on the demodulated signal undergone the erasure correction decoding process conducted by said erasure correction decoding means, by using said first error correction code, said error correction encoding means performing the error correction encoding process on the series of input digital information by using a convolutional code, said erasure correction encoding means performing the erasure correction encoding process on the series of digital information undergone the error correction encoding process performed by said error correction encoding means, by using a block code having the predetermined erasure correction capability, said erasure correction decoding means performing the erasure correction process on the demodulated signal on the basis of said block code, and said error correction decoding means performing the error correction process on the demodulated signal undergone the erasure correction process performed by said erasure correction decoding means, by using a viterbi decoder.
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3. A radio communication system comprising:
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a plurality of base stations arranged in a service area and connected to wired communication network; a plurality of mobile stations performing radio communication between a base station selected among them in TDD scheme via ground-system radio channel; and at least one orbiting satellite for performing the radio relay communication between said mobile station and base station or between mobile stations via satellite-system radio channel in TDD scheme with selective connection; each of said plurality of mobile stations and plurality of base stations including; radio channel selection means for selecting whether communication should be performed via said ground-system radio channel or said satellite-system radio channel; code selection means for selecting a first error correction code for giving priority to an error correcting capability if the ground-system radio channel is selected by said radio channel selection means, and selecting a second error correction code for giving priority to an erasure data correction capability if the satellite-system radio channel is selected by said radio channel selection means; encoding means for encoding input digital series, using said first and second error correction code selected by said code selection means; transmitting means for modulating the digital data series encoded by said encoding means in a predetermined digital modulation scheme, and then transmitting, within a predetermined transmission period the modulated digital data series to said ground-system radio channel or satellite-system radio channel selected by said radio channel selection means; receiving means for receiving a radio signal having reached within a predetermined receiving period via said ground-system or satellite-system radio channel, then demodulating the received signal, and outputting the demodulated signal; and decoding means for subjecting the demodulated signal output from said receiving means, to decoding processing based on said first error correction code wherein error correction is a matter of priority, if said first error correction code is selected by said code selection means, and for subjecting the demodulated signal output from said receiving means, to decoding processing based on said second error correction code wherein erasure data correction is a matter of priority, if said second error correction code is selected by said code selection means, thereby restoring erasure data whose reception has failed within said predetermined receiving period. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10)
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11. A radio communication apparatus for use in a radio communication system which performs TDD-scheme radio communication by selectively connecting, via a satellite-system radio channel, a plurality of radio communication apparatuses capable of performing TDD-scheme radio communication via a ground-system radio channel, the radio communication apparatus comprising:
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radio channel selection means for selecting whether communication should be performed via said ground-system radio channel or said satellite-system radio channel; code selection means for selecting a first error correction code for giving priority to an error correcting capability if the ground-system radio channel is selected by the radio channel selection means, and selecting a second error correction code for giving priority to an erasure data correcting capability if the satellite-system radio channel is selected by the radio channel selection means; encoding means for encoding input digital data series, using said first or second error correction code selected by said code selection means; transmission means for modulating the digital data series encoded by said encoding means in a predetermined modulation scheme, and then transmitting, within a predetermined transmission period, the modulated digital data series to said ground-system or satellite-system radio channel selected by said radio channel selection means; receiving means for receiving a radio signal having reached within a predetermined receiving period via said ground-system or satellite-system radio channel, then demodulating the received signal, and outputting the demodulated signal; and decoding means for subjecting the demodulated signal output from said receiving means, to decoding processing based on said first error correction code wherein error correction is a matter of priority, if said first error correction code is selected by said code selection means, and for subjecting the demodulated signal output from said receiving means, to decoding processing based on said second error correction code wherein erasure data correction is a matter of priority, if said second error correction code is selected by said code selection means, thereby restoring erasure data whose reception has failed within said predetermined receiving period.
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12. A radio communication system comprising:
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a first radio station and second radio station, at least, either of which is movable; and at least one orbiting satellite for relaying a radio signal transmitted between those radio stations in a TDD scheme; said first radio station including; encoding means for encoding a series of input digital information by using an error correction code having a predetermined erasure correction capability and including error correction encoding means for encoding the series of digital information by using a first error correction code having predetermined error correction capability, and erasure correction encoding means for encoding the series of digital information encoded by said error correction encoding means by using a second error correction code having a predetermined erasure correction capability, wherein the error correction encoding means and the erasure correction encoding means perform encoding processes using a first convolutional code and a first block code, respectively; and transmitting means for transmitting the series of digital information encoded by said encoding means to said orbiting satellite within a predetermined transmitting period, after modulating the series of digital information in a predetermined digital modulation scheme; said orbiting satellite including; relay receiving means for digital-demodulating the radio signal coming from said first radio station within a predetermined relay receiving period, after receiving the radio signal, and outputting the demodulated signal; relay decoding means for restoring erasure data not received within said predetermined relay receiving period, by performing the erasure correction decoding process on the demodulated signal outputted from said relay receiving means, on the basis of said error correction code, and including erasure correction decoding means for relay for restoring the erasure data, at first, by performing the erasure correction decoding process on the demodulated signal outputted from said relay receiving means on the basis of said second error correction code and based on a second block code, and error correction decoding means for relay for performing the correction process on the series of digital signals undergone the error correction process conducted by said erasure correction decoding means for relay, by using said first error correction code and using a first viterbi decoder; relay encoding means for encoding the series of signals undergone the erasure correction decoding process conducted by said relay decoding means, by using a relay error correction code having a predetermined erasure correction capability, and including error correction encoding means for relay for error correction encoding the series of digital signals encoded by said error correction decoding means for relay, by using the first relay error correction code having the predetermined error correction capability, and erasure correction encoding means for relay for encoding the series of digital signals encoded by said error correction encoding means for relay, by using the second relay error correction code having the predetermined erasure correction capability, wherein the error correction encoding means for relay and the erasure correction encoding means for relay perform encoding processing using a second convolutional code and a third block code, respectively; and relay transmission means for transmitting the series of signals encoded by said relay encoding means to said second radio station, within the predetermined relay transmitting period, after modulating the series of signals in the predetermined digital modulation scheme; said second radio station including; receiving means for outputting the demodulated signal by digital demodulation, after receiving the radio signal coming from said orbiting satellite within a predetermined receiving period; and decoding means for restoring the erasure information not received within said predetermined receiving period by decoding the erasure correction decoding process on the demodulated signal outputted from said receiving means on the basis of said relay error correction code, and including erasure correction decoding means for restoring the erasure data, by performing the erasure correction decoding process on the demodulated signal outputted from said receiving means on the basis of said second relay error correction code and based on a fourth block code, and error correction decoding means for performing the error correction process on the demodulated signal undergone the erasure correction decoding process conducted by said erasure correction decoding means, by using said first relay error correction code and using a second viterbi decoder.
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Specification