Blind time sequence error detection method and system suitable for low signal-to-noise ratio, and storage medium

Abstract

The invention discloses a blind time sequence error detection method and system suitable for a low signal-to-noise ratio, and a storage medium. The method comprises the steps: carrying out the frequency domain equalization of each subcarrier of each OFDM symbol, so as to eliminate the impact from a channel phase; judging each subcarrier of each OFDM symbol by adopting a timing error detection module so as to eliminate the influence of an information phase; subjecting each subcarrier of each OFDM symbol to an estimation operation to extract a timing error em. The key point of the invention is that the timing error detection module is mainly used for eliminating the influence of an information phase and extracting a timing error by using a timing error detection technology, so that only oneOFDM symbol needs to be estimated and calculated; the use of pilot frequency is avoided by using a judgment mechanism, so that the communication rate can be improved; a corresponding timing error is extracted by using an Early-late thought, and the timing error is sent to a loop filter. The method is suitable for a power line environment with a very low signal-to-noise ratio.

Description

technical field [0001] The present invention relates to the technical field of blind timing error detection, and more particularly, to a blind timing error detection method, system and storage medium suitable for low signal-to-noise ratio. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) is developed from MCM (Multi-Carrier Modulation, multi-carrier modulation). OFDM technology is one of the realization ways of multi-carrier transmission scheme. Its modulation and demodulation are realized based on IFFT and FFT respectively. It is a multi-carrier transmission scheme with the lowest complexity and widest application. The main idea of ​​OFDM is to divide the channel into several orthogonal sub-channels, convert high-speed data signals into parallel low-speed sub-data streams, and modulate them for transmission on each sub-channel. Orthogonal signals can be separated by using correlation techniques at the receiving end, which can reduce mutual in...

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Problems solved by technology

However, this method will inevitably reduce the rate due to the insertion of pilots. Secondly, because it uses two OFDM symbols before and after the differential operation, if it is in a low signal-to-noise ratio environment, it will inevitably introduce large noise, so the estimation error will be very large. This method is generally only suitable for environments with relatively good channel conditions.

In the power line environment, due to the large noise, the performance of the timing error is greatly deteriorated, so that the entire loop cannot converge to the expected value well.

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