Discrete Fourier transform based space-time combined inspecting device and method for radio transmission

Abstract

The spacialú¡temporal joint detection device and method based on discrete Fourier transform in wireless transmission concerns a equilibrious method and device based on wireless mobile communication field. The detective method of the device is as follows: a. making the spacialú¡tempora incorporation for estimated channel impulse response sequence to get new data sequence h(n); b. making the estimated channel impulse response sequence and received data sequence to carry out spacialú¡temporal incorporation to get new data sequence r^ (n); c: taking the non-normalization discrete Fourier transform for r ^(n), and getting transform coefficient R^(k); d. taking discrete Fourier transform for h (n), and taking the coefficient real part H (k) after transforming; e. handling H (k),R^(k) and estimating channel noise variance by equalizer to get new data sequence S^(k); f. taking non-normalization inverse discrete Fourier transform for S^(k) sequence, getting reconstructive sending data sequence S^ (n).

Description

1. Technical field: [0001] The present invention relates to an equalization method and device applied in the field of wireless mobile communication, in particular to a method and device for equalization of a wireless spread spectrum communication system under fading channel conditions. 2. Background technology: [0002] In the mobile communication transmission system, due to the multipath propagation of the wireless channel, it is very easy to cause intersymbol interference due to the influence of its channel characteristics. When the interference is seriously affected, the system must be corrected. The equalization technology is mainly to resist multipath fading. interference. In a digital communication system, if the channel frequency response within the system bandwidth is non-flat, then in the time domain, the impulse response of the channel will spread with time delay. This time delay spread is also called channel dispersion, and all time-division systems with channel ...

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Problems solved by technology

[0007] The MAP algorithm also has two disadvantages: one is that it needs to perform forward and backward recursive operations, because the recursive process contains a large number of exponential summation operations, so the computational overhead is very large; second, the decision delay of the MAP algorithm Larger, which leads to a large storage requirement. For the long frame transmission system, the huge storage space is extremely unfavorable for reducing the hardware overhead of the receiver.

The basis of OFDM is that the subcarriers must meet the requirements of orthogonality. If the orthogonality deteriorates, the performance of the entire system will be severely degraded, resulting in OFDM-specific intersubcarrier crosstalk.

In actual work, due to the time-varying nature of the wireless fading channel, it often causes frequency dispersion, causing Doppler frequency shift effect, thus affecting the carrier frequency orthogonality

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