Channel estimating method for high-speed moving orthogonal frequency division multiplying system

An orthogonal frequency division and channel estimation technology, applied in the direction of baseband system components, etc., can solve the problems of reduced receiver complexity, impractical wireless applications, poor accuracy, etc., to achieve good adaptability, simple equalization process, and low calculation effect of complexity

Inactive Publication Date: 2005-12-21
SHANGHAI JIAO TONG UNIV
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AI Technical Summary

Problems solved by technology

The equalizer cancels the ICI contained in the received carrier signal according to the estimated amplitude and derivative. Using this correlation, the complexity of the receiver can be sign

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  • Channel estimating method for high-speed moving orthogonal frequency division multiplying system
  • Channel estimating method for high-speed moving orthogonal frequency division multiplying system
  • Channel estimating method for high-speed moving orthogonal frequency division multiplying system

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Embodiment Construction

[0030] Such as figure 1 As shown, firstly, the data to be transmitted is processed by hybrid forward error correction coding and interleaving, and then constellation mapping (16QAM), IFFT spectrum shifting, and guard interval processing are performed, and the obtained data and pilot data form a data frame. After digital-to-analog conversion, quadrature modulator, and up-conversion, it is transmitted. The received signal first passes through a band-pass filter, and then undergoes down-conversion, analog quadrature demodulation, and analog-to-digital conversion. After de-guard interval processing, the data at the pilot position in each frame of data is separated from other transmission data. Next, send the data at the pilot position to the channel estimation unit in the present invention. After channel coefficient extraction and time-frequency bidirectional linear interpolation, the entire channel matrix is ​​obtained, and then the effective data is divided by the channel coeff...

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Abstract

The method includes steps: at sending end, pilot carrier data is inserted into time and frequency domains at same time; pilot carrier and data to be transmitted constitute data frame; at receiving end, pilot carrier and data in a frame are separated; pilot carrier data are sent to channel estimation part to calculate out each channel amplitude and phase at relevant position of carrier wave; thus, channel coefficients of center frequency point at sub carrier waves corresponding to each inserted position of pilot carrier are picked out; linear interpolation in frequency domain is carried out for channel coefficients; meanwhile linear interpolation in time domain is also carried out coefficients estimated so as to obtain whole matrix of channel coefficient. Equilibrium of receiving system in frequency domain is realize from received effective data divided by value of channel coefficient. Advantages are: low complexity, suitable to high moving speed and large multi paths time delay.

Description

technical field [0001] The invention relates to a channel estimation method in the wireless communication field, in particular to a channel estimation method for a high-speed mobile orthogonal frequency division multiplexing system. Background technique [0002] At present, the channel estimation technology of Orthogonal Frequency Division Multiplexing (OFDM) wireless transmission system can be roughly divided into LS (least square method), DFT (subspace estimation method), MMSE (minimum mean square error method), Turbo iterative detection method , neural network methods and various blind (blind or semi-blind) estimation methods. Among them, the first four methods can already be implemented with some specific hardware. LS, DFT, and MMSE algorithms have low complexity, and the cost of hardware implementation is relatively reasonable, but they are used in high-speed mobile environments and scattering environments with complex, maximum When the path delay is large, the accurac...

Claims

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Application Information

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IPC IPC(8): H04L25/02
Inventor 陈萍萍
Owner SHANGHAI JIAO TONG UNIV
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