Combined narrowband interference detection, elimination and channel estimation method based on continuous cyclic shift training sequence in OFDM system

Abstract

The present invention relates to a combined narrowband interference detection, elimination and channel estimation method based on a continuous cyclic shift training sequence in an OFDM system. On the condition of using two OFDM symbol training sequences to carry out the channel estimation, the method utilizes a signal detection and estimation technology and a training sequence design technology to realize the asynchronous narrowband interference detection, estimation and elimination, is applied to a the OFDM systems existing the narrowband interference, such as a wireless local area network IEEE802.11a, a wireless metropolitan area network WiMAX IEEE 802.16e, etc., realizes the accurate estimation and elimination of an asynchronous narrowband signal while realizing the interference robustness detection, and enables the training sequence auxiliary channel estimation performance on an interference condition to be improved effectively.

Description

technical field [0001] The present invention relates to an anti-narrowband interference channel estimation method in an OFDM system, specifically, to a method for realizing joint narrowband interference detection, estimation, elimination and channel estimation using two OFDM training symbols with continuous cyclic shift characteristics . Background technique [0002] With the explosive growth of wireless services, spectrum is a precious resource. Allowing multiple communication services to share spectrum is one of the feasible solutions to solve spectrum congestion. At present, in unlicensed frequency bands such as ISM (Industrial-Scientific-Medical), the coexistence of multiple communication systems has become a reality. When narrowband systems and OFDM-based broadband communication systems coexist, narrowband interference becomes an important issue to be considered in receiver design. Although cognitive radio technology can avoid interference through spectrum sensing, th...

AI Technical Summary

Problems solved by technology

Existing frequency-domain methods detect and eliminate narrow-band interference by setting thresholds, or use compressed sensing algorithms to estimate and eliminate interference. These methods are not robust to asynchronous narrow-band interference with frequency offset; time-domain methods first pass The time-domain linear filter locates the interference, and then uses the notch filter to filter out the interference. This kind of method converges slowly and the accuracy is not high.

Therefore, the existing research results can only deal with synchronous narrowband interference, or cannot accurately reconstruct narrowband interference, which has great limitations in performance

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