TRANSMITTER/RECEIVER FOR SPECTRUM DIFFUSION COMMUNICATION

摘要

PURPOSE:To contruct a practical system by using a specific code for diffusion of the spectra and defining the output level having the least dispersion of the absolute value of the correlative output as a demodulation signal out of those output levels of plural correlative sections. CONSTITUTION:A multiplication accumulator 24 products the exclusive OR to the received signal for each bit of a diffusion code and accumulates these ORs to output them in each cycle of the diffusion code. Then three accumulators 24 output the value obtained by accumulating the result of multiplication of the diffusion code and the received signal in the different accumulating sections only. A subtractor circuit 25 subtracts the reference value produced by a ROM 21 and a multiplication accumulator 22 from the outputs result of three accumulators 24. Then these output results are squared by a multiplication accumulator 26, and the dispersion is obtained from the reference value. These dispersions are accumulated. This accumulation result is inputted to a least value selecting circuit 27 and the least value is decided from three accumulated results. The demodulation signal with which the least dispersion is decided based on the reference value given from the accumulator 22 is outputted through the circuit 27.