Wireless communication system and transmit power and data rate control method therefor
First Claim
1. A wireless communication system transmitting data from a transmitting station to a receiving station using a plurality of subcarriers in parallel, wherein said transmitting station comprises:
- a channel quality judgment module judging the quality of a channel between said transmitting station and said receiving station for each of said plurality of subcarriers;
a channel coding module coding data signals into a code word;
a subcarrier modulation module dividing the code word into a plurality of subcarriers for modulation and modulating the subcarriers each composed of a plurality of symbols;
a multi-carrier modulation module combining the plurality of subcarrier-modulated symbols into transmission signals via frequency-time conversion; and
a data power setting module setting a transmission power for each of the plurality of subcarriers according to an output from said channel quality judgment module, wherein said receiving station comprises;
a demodulation module demodulating signals received from said transmitting station; and
a channel decoding module decoding the demodulated received signals, and wherein the transmission power is determined by a first control rule stipulating that, for the plurality of symbols transmitted at the same time, a transmission power for symbols corresponding to a first subcarrier whose channel quality is judged to be good is set higher than a transmission power for symbols corresponding to a second subcarrier whose channel quality is judged to be poor.
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Accused Products
Abstract
When channel-coded data is transmitted in a wireless communication system, coded data is divided into a plurality of bandwidths and the signal power is distributed to the bandwidths so that the communication channel capacity is increased. In addition, the transmission power is controlled on a time basis in such a way that the average power becomes larger when the channel quality is poorer so that the quality of each code word is stabilized. Alternatively, the coding rate is controlled in such a way that the data rate is decreased when the channel quality is poorer.
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Citations
20 Claims
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1. A wireless communication system transmitting data from a transmitting station to a receiving station using a plurality of subcarriers in parallel,
wherein said transmitting station comprises: -
a channel quality judgment module judging the quality of a channel between said transmitting station and said receiving station for each of said plurality of subcarriers;
a channel coding module coding data signals into a code word;
a subcarrier modulation module dividing the code word into a plurality of subcarriers for modulation and modulating the subcarriers each composed of a plurality of symbols;
a multi-carrier modulation module combining the plurality of subcarrier-modulated symbols into transmission signals via frequency-time conversion; and
a data power setting module setting a transmission power for each of the plurality of subcarriers according to an output from said channel quality judgment module, wherein said receiving station comprises;
a demodulation module demodulating signals received from said transmitting station; and
a channel decoding module decoding the demodulated received signals, and wherein the transmission power is determined by a first control rule stipulating that, for the plurality of symbols transmitted at the same time, a transmission power for symbols corresponding to a first subcarrier whose channel quality is judged to be good is set higher than a transmission power for symbols corresponding to a second subcarrier whose channel quality is judged to be poor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A data transmission control method for use by a transmitting station in a wireless communication system transmitting data from the transmitting station to a receiving station using a plurality of subcarriers in parallel, said method comprising the steps of:
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judging the quality of a channel between said transmitting station and said receiving station for each of said plurality of subcarriers;
coding, by said transmitting station, data signals, which is to be transmitted to said receiving station, for generating a code word;
dividing the code word into a plurality of subcarriers for modulation and generating a plurality of symbols;
combining the plurality of symbols into transmission signals via frequency-time conversion; and
setting a transmission power for each of the plurality of subcarriers according to the judged channel quality and transmitting the transmission signals to said receiving station, wherein the transmission power is determined by a first control rule stipulating that, for the plurality of symbols transmitted at the same time, a transmission power for symbols corresponding to a first subcarrier whose channel quality is judged to be good is set higher than a transmission power for symbols corresponding to a second subcarrier whose channel quality is judged to be poor. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. A transmitting station transmitting data to a receiving station using a plurality of subcarriers in parallel, comprising:
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a channel quality judgment module judging the quality of a channel between said transmitting station and said receiving station for each of said-plurality of subcarriers;
a channel coding module coding data signals into a code word;
a subcarrier modulation module dividing the code word into a plurality of subcarriers for modulation and modulating the subcarriers each composed of a plurality of symbols;
a multi-carrier modulation module performing frequency-time conversion for the plurality of subcarrier-modulated symbols to generate transmission signals; and
a data power setting module setting a transmission power for each of the plurality of subcarriers according to an output from said channel quality judgment module, and wherein the transmission power is determined by a first control rule stipulating that, for the plurality of symbols transmitted at the same time, a transmission power for symbols corresponding to a first subcarrier whose channel quality is judged to be good is set higher than a transmission power for symbols corresponding to a second subcarrier whose channel quality is judged to be poor. - View Dependent Claims (18, 19, 20)
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Specification