Time frequency optimum channel estimation method in OFDM mobile communication system

A mobile communication system, orthogonal frequency division technology, applied in the field of channel estimation of orthogonal frequency division multiplexing system, can solve the problems of channel estimation performance deterioration, spectrum leakage, no data transmission, etc., and achieve the effect of overcoming performance deterioration

Active Publication Date: 2008-08-27
HUAWEI TECH CO LTD
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Problems solved by technology

[0005] However, in the actual OFDM system, in order to consider the physical realizability of the shaping filter, some subcarriers in the filter roll-off domain, that is, the edge of the allocated bandwidth, are not used for data transmission, that is, the actual OFDM The system must take into account the guard band
The existence of the guard band makes the FFT-based frequency domain filtering produce spectral leakage, which leads to the deterioration of channel estimation performance
On the other hand, FFT-based time-domain interpolation or filtering will also lead to deterioration of channel estimation performance when the terminal moves at high speed

Method used

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  • Time frequency optimum channel estimation method in OFDM mobile communication system
  • Time frequency optimum channel estimation method in OFDM mobile communication system
  • Time frequency optimum channel estimation method in OFDM mobile communication system

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Embodiment Construction

[0023] The specific implementation of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0024] figure 1 is a schematic diagram of the time-domain and frequency-domain two-dimensional pilot structure used in the present invention, wherein solid circles represent pilot symbols, and blank circles represent data symbols. In this structure, the time domain length is N, and the frequency domain length is K. The interval of pilot symbols in the frequency direction is D f , the interval in the time direction is D t . The number of pilot symbols in frequency direction and time direction is L respectively F and L T .

[0025] Step 1. Construct a two-dimensional pilot data structure in the time domain and frequency domain at the sending end

[0026] Let X(n u , k v ) means the nth u OFDM block kth v Pilot symbols at subcarriers, where 0≤u≤L T -1, 0≤v≤L F -1, then there is

[0027] X(n u , k v ...

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Abstract

Disclosed is an optimum time-frequency channel estimation method in an orthogonal frequency division multiplexing mobile communication system, including the following steps: step one, a time-domain and frequency-domain two-dimensional pilot frequency data organization is constructed at a sending terminal; step two, the least-squares estimation of the channel parameters of pilot frequency symbols at a receiving terminal; step three, single-point filtering is carried out to the channel parameters of the pilot frequency symbols in a two-dimensional discrete cosine transform region and the channel parameters at all the data symbols are acquired through expanding the discrete cosine transform. The channel estimation method overcomes the problem that conventional OFDM channel estimation methods deteriorate in performance in the case that the system is provided with a lunge strap or that the terminal moves with great speed, and is capable of realizing almost optimum estimation performance with low degree of complexity.

Description

technical field [0001] The invention relates to a channel estimation algorithm of a wireless mobile communication system, in particular to a channel estimation method of an Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) system. Background technique [0002] OFDM technology is a representative technology in multi-carrier parallel transmission. Because of its strong anti-multipath fading ability, insensitivity to narrow-band interference and narrow-band noise, flexible bandwidth expansion and support for variable user rates, it has been widely used. attention and more and more applications. [0003] In wireless communication systems, coherent detection has a performance gain of 3-4dB more than non-coherent detection, so coherent detection technology is often used. In order to realize coherent detection, channel estimation needs to be performed at the receiving end. In order to estimate channel parameters timely and accurately, p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/02H04L27/26
Inventor 高西奇江彬王闻今吴大焰尤肖虎
Owner HUAWEI TECH CO LTD
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