Method for reducing multicarrier signal peak level ratio

Abstract

A method of reducing peak level ratio of multi-carrier wave signals is to set a pulse signal generator in a down-stream base band or intermediate frequency modulation, to set a threshold of reducing peak level ratio on time-domain to amplitude peak value of multi-carrier wave signals; if it exceeds the threshold, then to record the character parameters of the peak value to be trans furred to each pulse generator, to generate related pulse according to above mentioned parameters and each channel of different single carrier singles making up of the multi-carrier signals, to be overlapped on the signal to cancel the peak value reduced to the threshold after combination to reduce multi-carrier signal peak level ratio. If its peak value doesn't exceed threshold, nothing can be done.

Description

(1) Technical field [0001] The invention relates to a method for reducing the signal peak-to-average ratio in the downlink modulation link of a multi-carrier broadband system. (2) Background technology [0002] Since the size of the base station can be effectively reduced and the cost of the base station can be reduced, the multi-carrier technology has received widespread attention and research at present. Moreover, people also hope to use multi-carrier technology to achieve high bit rate transmission in multi-path fading channels. [0003] However, one of the disadvantages of the multi-carrier communication system is that when the number of sub-carriers increases, the peak-to-average ratio of the transmitted signal will also increase. Because if each single-carrier signal is regarded as a cosine signal with random phase, the multi-carrier signal synthesized after the superposition of several single-carrier signals must have an amplitude envelope fluctuation that is not con...

AI Technical Summary

Problems solved by technology

Direct clipping can effectively reduce the signal peak-to-average ratio, but it is easy to cause in-band noise interference and out-of-band spectrum regeneration of the modulated signal, affecting adjacent channels and system capacity; for existing systems, redesign The spread spectrum code will bring a series of problems; changing the initial phase of the subcarrier signal is not operable, and it is difficult to implement; superimposing out-of-band artificial signals, such as artificial amplitude modulation signals modulated outside the band, can reduce multi-carrier Signal peak-to-average ratio, but in the actual system, it takes a relatively high cost to design a filter at the radio frequency end to filter out the out-of-band signal

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