Compressed sensing based sparse channel estimation method in two-way relay network

Abstract

The invention discloses a compressed sensing based sparse channel estimation method in a two-way relay network. The method includes: according to actual signals received in a second time slot by a current user terminal and a Gaussian random training sequence sent by each user terminal in the two-way relay network, subjecting an equivalent channel vector between the current user terminal and a relay node to channel iterative loop estimation to obtain a channel estimation value; and using a weighted least square estimation method during channel iterative loop estimation to continuously weaken influences of abnormal samples corresponding to positions with large residual values after the last iteration and enhance attention to favorable samples corresponding to positions with small residual values, so that precision and robustness in sparse two-way relay channel estimation can be effectively improved. Further, since the compressed sensing based sparse channel estimation method in the two-way relay network makes full use of potential sparse characteristics of two-way relay channels, the Gaussian random training sequences required by estimation can be greatly reduced, estimation efficiency is improved, and energy and bandwidth utilization rate is greatly increased.

Description

technical field [0001] The invention relates to a channel estimation method in a wireless communication system, in particular to a sparse channel estimation method based on compressed sensing in a two-way relay network. Background technique [0002] As a key technology that can meet the high-capacity requirements of future wireless broadband communication systems, relay technology has become a research hotspot in the field of communication in recent years. For the research on relay technology, the early stage mainly focused on the one-way relay (One-Way Relay) system. However, the inherent defect of the one-way relay system is that as the number of relay nodes increases, the spectral efficiency will gradually decrease. Aiming at the inherent defects of the one-way relay system, researchers represented by Shannon proposed the concept of a two-way relay (Two-Way Relay) system. A large number of studies have shown that the biggest advantage of the two-way relay system over the...

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Problems solved by technology

The two-way relay channel estimation method based on the traditional least squares method does not consider the potential sparse characteristics of the two-way relay channel, which will lead to excessive use of energy and bandwidth, and the channel estimation efficiency is not high, which violates the prevailing "green communication" in recent years. The idea of ​​energy saving and emission reduction in the concept; the two-way relay channel estimation method based on the orthogonal matching pursuit method in the compressed sensing theory is a new channel estimation method based on the compressed sensing theory, which fully considers the actual The potential sparseness of the two-way relay channel can significantly reduce the training sequence required for channel estimation and improve energy and bandwidth utilization while obtaining the same estimation effect as the traditional two-way relay channel estimation method based on the least squares method. However, since the orthogonal matching pursuit method itself is a greedy iterative method, the least squares is directly used to estimate the new approximation value in each iteration process, ignoring the abnormal samples corresponding to the positions with larger residual values ​​after the previous iteration. Therefore, the final estimation result will be less accurate, and the efficiency of channel estimation will be reduced

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