A High Dynamic Frequency Offset Estimation Method Based on Joint Iterative Decoding

Abstract

The invention discloses a high dynamic frequency offset estimation method based on joint iterative decoding. The method fully utilizes the channel coding structure, uses the soft information output by the decoder to estimate the frequency offset, and calculates the frequency offset value obtained by the frequency offset estimation. Compensate the received signal. The present invention establishes an estimation expression including high-order frequency offset variables based on the maximum likelihood criterion, and simplifies the high-order frequency offset variables through enumeration. Use the simplified expression to obtain the estimated value of the first-order frequency offset by using Discrete Fourier Transform (DFT for short), and under different high-order frequency offset estimated variables listed, the estimated expression obtained by using DFT is the largest Values ​​are compared to obtain the estimated value of the target frequency offset. The method can be used to estimate the frequency offset under the condition of relatively bad channel environment, and can obtain a frequency offset estimation value with high precision.

Description

technical field [0001] The invention relates to the technical field of satellite communication reception, in particular to a high dynamic frequency offset estimation method based on joint iterative decoding. Background technique [0002] As an extension of the ground communication network, satellite communication can achieve communication coverage in places that are difficult to reach by the ground communication network. However, the special environment of the satellite communication channel makes it difficult to apply the commonly used ground receiving technology to satellite communication receivers. Generally, the satellite is in a high-speed moving state, and there is a large Doppler frequency deviation in the communication channel, and because the satellite does not move at a uniform speed, the Doppler frequency deviation is often a high-order variable. [0003] Common receiving synchronization technologies include data-assisted synchronization technology, non-data-assis...

AI Technical Summary

Problems solved by technology

Common data-assisted synchronization methods include pilot-assisted algorithms such as Kay algorithm, Fitz algorithm, L&R algorithm, and M&M algorithm. These algorithms have different computational complexity and applicable application scenarios, and are characterized by large estimation range and low estimation accuracy.

The estimation range of code-assisted synchronization technology is smaller than that of data-assisted synchronization technology, but the estimation accuracy is higher and the complexity is larger, and the current existing algorithm is for the estimation of constant frequency offset

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