Channel estimation method and apparatus for OFDM of transmission diversity

A technology of channel estimation and transmit diversity, which is applied in the field of OFDM channel estimation, and can solve problems such as difficulty in controlling the peak-to-average power ratio of the transmit time-domain waveform, low signal-to-noise ratio, and difficulty in achieving high-precision channel estimation.

Inactive Publication Date: 2007-12-05
CENT ACADEME OF SVA GROUP
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Problems solved by technology

However, space-time decoding requires accurate channel parameter information. For OFDM wireless transmission channel estimation with transmit diversity technology, when estimating the channel parameters between an antenna link pair, it will be affected by other transmitting and receiving antennas at the same time. Interference between link pairs, so the signal-to-noise ratio is very low when estimating, and it is difficult to achieve high-precision channel estimation
The usual method is to insert specially designed pilot data at different positions of different antennas when the frequency domain data is multiplexed at the transmitting end, so that the pilot data received by the receiving end after the attenuation of each transmit-receive antenna link pair The data can be staggered in the frequency domain to complete the estimation of the channel parameters between each antenna link pair, but inserting the pilot in the frequency domain will make it difficult to control the peak-to-average power ratio of the transmitted time-domain waveform, so the time-domain pilot is selected The insertion technique has a better peak-to-average power ratio gain than the frequency-domain pilot insertion technique

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  • Channel estimation method and apparatus for OFDM of transmission diversity
  • Channel estimation method and apparatus for OFDM of transmission diversity
  • Channel estimation method and apparatus for OFDM of transmission diversity

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Embodiment approach

[0039] As shown in Figure 1, the present invention provides a channel estimation method of transmit diversity OFDM, comprising the following steps:

[0040] Step 1. Process the two channels of modulated data at the transmitter to obtain valid data X in the time domain Di , (i=1, 2);

[0041] Step 1.1, performing serial-to-parallel conversion on the two-way modulated data at the transmitter in the serial-to-parallel conversion circuit;

[0042] Step 1.2, performing space-time encoding processing on the data output in step 1.1 in a space-time encoder;

[0043] Step 1.3, respectively perform N-point IFFT (inverse fast Fourier transform) operation on the two output signals output in step 1.2 to obtain time-domain effective data X D1 and x D2 ;

[0044] Step 2, the pilot data generation unit simultaneously generates the time-domain pilot data sequences required by the two transmitting antennas:

[0045] x P =[exp(j*2π*B*0*(0:1:L+K-1) / N)L exp(j*2π*B*k*(0:1:L+K-1) / N )L] 1×b ...

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Abstract

The invention provides an equipment and method for channel estimate of Orthogonal Frequency Division Multiplexing, which using the principle that the linear system doesn't change the response form for the complex exponent signal. Insert the complex exponent form in each frame of time domain's pilot frequency block data. Using the estimate technology and FFT processing obtain OFDM channel frequency range coefficient in a data frame. And stagger the position between each launch - receiving antenna link in the time. The pilot frequency data has the permanent enveloping characteristic in the time domain. The OFDM channel has good estimate precision by using average noise reduction processing. The entire channel installment also has low computation complexity.

Description

technical field [0001] The present invention relates to a communication signal processing method and device, in particular to a channel estimation method and device of OFDM (Orthogonal Frequency Division Multiplexing) with transmit diversity. Background technique [0002] Future mobile communication systems need to provide high-speed data transmission capabilities. OFDM can convert frequency-selective wireless channels into a group of parallel frequency-flat fading channels, so that each sub-channel can use a simple single tap to achieve effective channel equalization. At the same time , the bandwidth of each sub-channel is narrowed, making the duration of the symbol longer, and the intersymbol interference can be eliminated by using the cyclic prefix processing. Therefore, OFDM technology has been increasingly widely used in broadband wireless access WLAN and WiMAX, digital video transmission DVB-T and digital multimedia broadcasting DMB and other fields. [0003] Diversit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L1/06H04L25/02H04L27/26
Inventor 吴美武
Owner CENT ACADEME OF SVA GROUP
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