Signal transmission/reception system of orthogonal frequency division multiplexing

A transmission apparatus of orthogonal frequency division multiplexing for transmitting a signal on which a plurality of carriers are multiplexed, said carriers being orthogonal to one another, said transmission apparatus comprising:

• a first error correction coding circuit for converting a first code to a first error correction code;
• a second error correction coding circuit for converting a second code to a second error correction code which has error correcting performance higher than said first error correction code;
• a first modulator for outputting a signal modulated with said first error correction code in accordance with a modulation scheme which can be applied with a synchronous detection for demodulation;
• a second modulator for outputting a signal modulated with said second error correction code in accordance with a predetermined modulation scheme;
• and
• a distributing circuit for distributing the signal modulated by said first modulator and the signal modulated by said second modulator to a plurality of predetermined carriers, said distributing circuit distributing the signal modulated by said second modulator to all or some of carriers existing within a predetermined number of columns from at least one of both end regions of a signal transmission frequency band, and assigning the signal modulated by said first modulator to the remaining carriers.

A transmission/reception system of orthogonal frequency division multiplexing having a transmitter for transmitting a signal on which a plurality of carriers are multiplexed, said carriers being orthogonal to one another, and a receiver for receiving and demodulating a transmitted signal, wherein said transmitter comprises:

• a first modulator for outputting a code modulated in accordance a modulation scheme which can be applied with a synchronous detection for demodulation;
• a second modulator for outputting a code modulated in accordance with a modulation scheme different from the modulation scheme associated with said first modulator;
• and
• a distributing circuit for distributing the codes modulated by said first and second modulator to a plurality of predetermined carriers, wherein said distributing circuit distributes the code modulated by said second modulator to all or some of carriers existing within a predetermined number of columns from at least one of both end regions of a signal transmission frequency band, and the code modulated by said first modulator to the remaining carriers.

A transmission/reception system of orthogonal frequency division multiplexing having a transmitter for modulating a plurality of carriers with a plurality of signals to transmit the signals, said carriers being orthogonal to one another, and a receiver for receiving and demodulating a transmitted signal, wherein said transmitter comprises:

• a first error correction coding circuit for converting a first code to a first error correction code;
• a second error correction coding circuit for converting a second code to a second error correction code which has error correcting performance higher than said first error correction code;
• a first modulator for outputting a signal modulated with said first error correction code in accordance with a modulation scheme which can be applied with a synchronous detection for demodulation;
• a second modulator for outputting a signal modulated with said second error correction code in accordance with a predetermined modulation scheme;
• and
• a distributing circuit for distributing the signal modulated by said first modulator and the signal modulated by said second modulator to a plurality of predetermined carriers, said distributing circuit distributes the signal modulated by said second modulator to all or some of carriers existing within a predetermined number of columns from at least one of both end regions of a signal transmission frequency band, and assigning the signal modulated by said first modulator to the remaining carriers.