TRANSMITTER, RECEIVER, TRANSMITTING METHOD, AND RECEIVING METHOD

摘要

PROBLEM TO BE SOLVED: To reduce the sizes, prices, and power consumption of a transmitter and a receiver by making the symbols of all users to be able to be multiplexed/ separated upon and from users by means of a small-sized user transmission- reception processing circuit even when the number of the users upon which the symbols are multiplexed is increased. SOLUTION: When the transmitter performs user multiplexing processing through frequency region diffusion, 1-bit cyclic shift registers 114-117 having the same length as that of codes cyclically shift diffused codes having sharp autocorrelation peaks. While all user identification codes are successively generated by the shifting, multipliers 118-121 respectively multiply all user identification codes by subcarrier symbols from a copying section 109. After adders 122-125 and registers 126-129 accumulate the multiplied results of the multipliers 118-121 at every subcarrier, multipliers 134-137 respectively multiply the accumulated multiplied results by subcarrier waveforms. Then the symbols are multiplexed upon the users by adding all results to each other by means of an adder 138 and the multiplexed results are transmitted by using multiple carriers.