Trellis coding spread spectrum communication system and trellis coding spread spectrum communication method

Abstract

The invention discloses a trellis coding spread spectrum communication system and a trellis coding spread spectrum communication method, and relates to the technical field of spread spectrum communication. In order to increase the coding gain of the spread spectrum communication system, the method makes use of the principle of trellis coding to complete optimal division of a signal space; moreover, the generated modulation coding signal sequences have maximum Euclidean distance, and the spread spectrum modulation output of the coded signal sequences is balanced modulation of suppressed carrier; and the demodulation of a receiving terminal is realized by means of Viterbi soft decoding. The spread spectrum communication system comprises at least one trellis coding and spread spectrum modulation device, a radio frequency transmitting device, a radio frequency receiving device and at least one despread and Viterbi soft decoding device, wherein the trellis coding and spread spectrum modulation device or method can obtain 3 to 6dB coding gain compared with the prior uncoded spread spectrum modulation device or method, and reduces the transmitting power of a transmitter.

Description

technical field [0001] The invention relates to a spread spectrum communication system, which is used in the second generation mobile communication system CDMA one, the third generation mobile communication system WCDMA, cdma2000, TD-SCDMA, satellite communication system and other spread spectrum communication systems. Background technique [0002] From the 1990s to the present, with the development of digital technology, the global mobile wireless communication system has developed rapidly, from the first generation of analog products for commercial use to the second generation of digital mobile communication systems designed for the public and business environment. In the mid-1990s, the world's first mobile communication equipment manufacturers and operators have entered the stage of specific planning, design and implementation from the stage of conceptual approval of the third-generation mobile communication system. [0003] The CDMA one in the second generation mobile co...

AI Technical Summary

Problems solved by technology

This method has the following two problems: (1) It is a hard decision before decoding, and a part of useful information will be lost. Usually, the hard decision demodulation will lose about 2dB in the signal-to-noise ratio

However, when the sequence is optimally decoded using the Hamming distance as the measure, the coding symbol that is the best for the Hamming distance cannot obtain a good Euclidean distance structure when it is mapped to a non-binary modulated signal

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