Channel estimating method based on circulation orthogonal sequence in multi-relay cooperative communication system

Abstract

The invention discloses a channel estimating method based on circulation orthogonal sequence in a multi-relay cooperative communication system, through which reliability and efficiency of the multi-relay cooperative communication can be increased obviously. In the designed relay system, the source node broadcast transmits a channel training sequence having circulation orthogonal characteristics, each relay node forwards the received channel training sequence to the target node after circulation shift of different intervals. Through the signal received by the target node is superimposition of the channel training sequences forwarded by each relay, the target node can accurately estimate the source node-target node channel through each relay by using the orthogonality among the training sequences forwarded by each relay. The method has the advantages that high-precision channel estimation can be finished with low operation complexity and low training time cost, and the estimation error and the time cost will not be increased as the increase of the relay number, and the method is suitable for the cooperative communication system having a large number of relays.

Description

Technical field [0001] The invention relates to the field of digital communication signal processing, in particular to a channel estimation method based on cyclic orthogonal sequences in a multi-relay cooperative communication system. Background technique [0002] In wireless communication, the frequency selective fading caused by the multipath channel will affect the reliability of signal transmission and deteriorate the transmission performance. When the signal bandwidth increases, the influence of frequency selective fading will be more obvious. In addition, deep fading will also occur in wireless communication, making it difficult to establish or maintain a communication link. Therefore, the traditional end-to-end single-antenna system has limited ability to resist multipath and deep fading systems, and it is difficult to meet the high-speed and high-bandwidth requirements of next-generation mobile communications. Therefore, the multi-antenna system (MIMO) is introduced, whi...

AI Technical Summary

Problems solved by technology

If the time division multiplexing method requires higher estimation accuracy, a longer training sequence is required, but the efficiency will be greatly reduced as the number of relays increases. If the efficiency is to be ensured, a shorter training sequence is required, and the estimation accuracy will decrease. Therefore, it is reduced; in the frequency division multiplexing method, interpolation is required, and the interpolation error increases when the number of relays is large, and the performance drops significantly

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