Method and device for decoding iterated internal code and evaluating channel for orthogonal frequency division multiplexing system

Abstract

The invention discloses a method and a device for decoding an iterated internal code and evaluating a channel for an orthogonal frequency division multiplexing system. The iterating method comprises the following steps: at a transmitting end, carrying out internal code encoding and intraframe interleaving by a code with a long short code; at a receiving end, calculating circular convolution of an OFDM time domain data block and an evaluation value of channel time domain impulse response based on an initial evaluation value of the channel time domain impulse response; completing constellation de-mapping according to the channel evaluation and the result of circular convolution to acquire bit soft information; carrying out intraframe de-interleaving and internal code decoding on the bit soft information to acquire decoded bit soft information, carrying out intraframe interleaving on the decoded bit soft information, and remapping the constellation; and updating the evaluation value of the channel time domain impulse response according to the remapped result, and carrying out channel evaluation post-treatment. The method and the device can improve channel evaluation precision, and reduce system error rate, thereby improving system performance, in particular mobile performance, and ensuring complexity and controllable time delay of the system.

Description

technical field [0001] The invention relates to the technical field of digital information transmission, in particular to an iterative inner code decoding and channel estimation method and device for an orthogonal frequency division multiplexing system. Background technique [0002] Broadband wireless transmission faces the problem of frequency selective fading caused by multipath effect. OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) technology can effectively combat multipath effects, and has been widely used in wireless communication systems such as wireless local area network, wireless metropolitan area network, digital audio and video broadcasting. [0003] In the OFDM system of wireless communication, the accurate channel frequency domain response or time domain impulse response directly affects the working performance of the system. The received signal at the receiving end is the result of the convolution of the transmit...

AI Technical Summary

Problems solved by technology

Due to the multipath effect in the transmission process, the training sequence is not only interfered by noise at the receiving end, but also interfered by data

When directly using the training sequence for estimation, the accuracy of the channel estimation result is low, especially when there is a large Doppler shift, the performance will drop sharply

There are also OFDM systems in the prior art that use long code decoding and long interleaving for decoding and channel estimation. This method will drastically increase the complexity and delay of the system, and the channel estimation accuracy is low, and the system bit error rate is low. high

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