COMMUNICATION SYSTEM WITH REDUCED POWER VARIATION AND METHOD THEREFOR

摘要

The invention relates to a communication system employing subchannel communication such as OFDM or multicode CDMA. A significant disadvantage of subchannel communication is the power variation of the transmitted signal. The invention provides a system and method with reduced power variation without compromising performance or increasing transmission bandwidth. According to the invention the information symbols to be transmitted on the individual subchannel are fed to encoders (809-815) which maps the information symbols into channel symbols by increasing the order of the symbols. The encoding is both in response to a forward error correction scheme and includes selection between redundant symbol values to reduce power variation of the combined signal. The channel symbols are fed to a modulator (309) and the modulated signal is transmitted. Preferably the encoder comprises a trellis coder jointly encoding the information symbols and compensation data set to reduce the power level variation.