Carrier frequency error estimation and compensation system and method of multi-carrier spread spectrum communication

Abstract

The invention discloses a carrier frequency error estimation and compensation system and method of multi-carrier spread spectrum communication. A communication device in the system comprises a signal transmitting device and a signal receiving device. The signal receiving device is composed of a carrier frequency separator, a carrier frequency error estimation, compensation and despreading unit, a data demodulator and a decoder, wherein the carrier frequency separator, the carrier frequency error estimation, compensation and dispreading unit, the data demodulator and the decoder are sequentially connected. A spread spectrum modulation unit in the signal transmitting device performs spread spectrum modulation on data which are coded by a coder, the carrier modulation unit performs multi-carrier modulation which meets the orthogonality condition on signals which undergo spread spectrum, and the signals are transmitted to the signal receiving device through a wireless channel. According to the received signals in the signal receiving device, the carrier frequency separator is used sequentially used for performing frequency separating on all received sub-carriers, the sub-carriers undergo carrier frequency error estimation and compensation and are despread by the despreading unit, the signals are demodulated by the data demodulator, and finally the data are obtained by being decoded by the decoder. The carrier frequency error estimation and compensation system and method have high adaptability and low complexity.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a wireless multi-carrier spread spectrum communication system, and in particular to estimation and compensation of carrier frequency errors. Background technique [0002] The wireless channel has the characteristics of frequency selective attenuation and is affected by the multipath effect. In the existing wireless communication technology, in order to overcome the above problems, the multi-carrier modulation technology is mainly used, that is, the orthogonal frequency division multiplexing technology and the spread spectrum technology. Combination, that is, using multi-carrier spread spectrum communication system to realize data transmission. However, although the existing technical solutions of the multi-carrier spread spectrum communication system have high modulation efficiency and achieve a satisfactory transmission rate, the receiving mechanism of OFDM is com...

AI Technical Summary

Problems solved by technology

However, although the existing technical solutions of the multi-carrier spread spectrum communication system have high modulation efficiency and achieve a satisfactory transmission rate, the receiving mechanism of OFDM is complicated, and the required protocol is also complicated. , the construction cost is high, and at the same time, because OFDM is realized by fast Fourier transform, the frequency interval between it and the carrier is fixed and reaches the minimum. Any error in the carrier frequency caused by the Puler effect and clock deviation, the carrier frequency will lose its orthogonality and generate large inter-carrier interference, making the reliability and adaptability of the communication system unsatisfactory

In order to overcome the performance degradation caused by the carrier frequency error in the multi-carrier spread spectrum communication system, it is necessary to develop the estimation of the carrier frequency error and make corresponding compensation, but the methods developed so far all have high calculation Complexity, difficult to truly implement in a real-time communication system

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