Frequency deviation estimation method based on noise subspace

Abstract

The invention discloses a frequency deviation estimation method based on the noise subspace, which comprises the steps of: calculating a phase angle rotational component caused by the frequency deviation according to a received time domain signal; averaging and normalizing the phase angle rotational component to obtain a corresponding fine frequency deviation estimation value; carrying out fine frequency deviation correction on the sequence of the received time domain signal; compensating the corrected time domain signal with an Epsilon phase; carrying out N-point Discrete Fourier Transform on the compensated signal; removing symbols modulated on a subcarrier; carrying out M-point Inverse Discrete Fourier Transform to obtain a time domain signal with the length M; computing the sum of the modulus squares of G values at the head of the time domain signal with the length M and M to G values at the end of the time domain signal with the length M and calculating the minimum ratio of the modulus squares to provide the estimated value of a coarse frequency deviation; and adding the estimated coarse frequency deviation value with the fine frequency deviation value to obtain the total frequency deviation estimation value. The invention is suitable for various block transmitting systems, including OFDM, with cyclic prefixes, and has the advantages of speediness, reliability, light load, wide capture range, high estimation precision, low complexity for implementation and like.

Description

technical field The invention relates to a frequency synchronization method applied to an Orthogonal Frequency Division Multiplexing (OFDM) system, which belongs to the technical field of mobile communication synchronization, and specifically relates to a method that is fast, reliable, relatively small in load, large in capture range, high in estimation accuracy, and complex in implementation. Low-degree frequency offset estimation method based on noise subspace. Background technique Frequency synchronization is a prerequisite for normal communication in a mobile communication system. In order to support high-speed data services, the future mobile communication system will be a broadband, multi-antenna system, and OFDM is an important candidate for the future mobile communication system. For future mobile wireless communication, the difference between the crystal oscillators at the two ends of the transceiver will affect the carrier frequency and cause it to shift, thereby ...

AI Technical Summary

Problems solved by technology

The traditional frequency synchronization methods are either based on the frequency domain training sequence or the time domain training sequence to estimate the carrier frequency offset. They all have such shortcomings: not suitable for packet data transmission, high load, small capture range, Unsatisfactory estimation performance and high computational complexity

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