Single-carrier time frequency mixing equalization method and device

Abstract

The invention discloses a single-carrier time frequency mixing equalization method which comprises the following steps: carrying out channel estimation in a time domain by adopting a channel estimation algorithm according to the characteristics of the known training sequence, and estimating the time domain channel response; transforming the received data and the time domain channel response into a frequency domain, and carrying out frequency domain equalization; after frequency domain equalization, carrying out inverse fast Fourier transform (IFFT), and recovering the time domain data after the frequency domain is equalized for the first time; and forecasting the color noise of the current time and eliminating the color noise in the time domain, thereby realizing the whitening of the color noise spectrum, and finishing the single-carrier time frequency mixing equalization. The invention also discloses a low-complexity single-carrier time frequency mixing equalization device. The invention has good performance in the aspect of resisting multipath fading channels, can obviously improve the frequency domain equalization performance of deep fading channels, and is suitable for digitaltelevision ground transmission systems and data communication systems.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a signal equalization method in a data communication system. The invention also relates to a device for realizing the signal equalization method. Background technique [0002] In wireless communication, data transmission faces severe multipath delay, resulting in inter-symbol interference (ISI). In terms of countering multipath fading channels, the basic technologies can be divided into two categories: single carrier transmission and multi-carrier transmission. For a single-carrier system, time-domain equalization is generally used to eliminate ISI, but the calculation cost of time-domain equalization for a single carrier is high. In the ATSC (8VSB) digital television terrestrial transmission system in the United States, even if the equalizer tap order of the receiver has reached hundreds of orders, it can only deal with static multipath of tens of microseconds. Dynamic multip...

AI Technical Summary

Problems solved by technology

However, due to frequency domain equalization [including zero-forcing equalization and MMSE (Minimum mean-squared-error, minimum mean square error) equalization] in the case of countering deep fading channels, there is residual ISI and the influence of colored noise on the signal, which restricts the single-carrier frequency The performance of domain balancing, in order to solve this problem, some people have done research on it

David Fal coner et al proposed a FD-DFE (Frequency Domain Judgment Feedback equalization) single-carrier frequency domain equalization structure, because the feedforward FDE (Frequency-Domain-Equalizaion, frequency domain equalization) and feedback DFE (Decision-Feedback-Equal i zation, decision feedback equalization) coefficients are linked , which affects the flexibility of the system, and under conditions of low SNR (signal-to-noise ratio), this form of decision feedback is more likely to cause error diffusion

YuZhu and Khaled Ben proposed FDE-NP (Frequency Domain Equalization Noise Prediction) in the document "Single Carrier Frequency Domain Equalization with Time Domain Noise Prediction for Wideband Wireless Communications" (IEEE Transactions on wireless communications, Vol.5, NO.12, December 2005) The structure, which optimizes the frequency domain equalization coefficient and the noise prediction coefficient independently, reduces the complexity, but due to too few feedback taps, the performance is not ideal

In the US patent US20040021795A1, a structure of frequency domain equalization plus time domain noise prediction is also mentioned, but this structure adopts a hard judgment method, the error diffusion is large, and to obtain better performance, multi-stage tap coefficients are required, and hardware overhead Big

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