Method for correcting phase demodulating error of orthogonal frequency multichannel signal

A multi-channel signal and phase demodulation technology, applied in multi-frequency code systems, multi-carrier systems, etc., can solve problems such as phase errors

CN101924730BInactive Publication Date: 2012-07-04BEIJING INSTITUTE OF TECHNOLOGYGY
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2012-07-04
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a method for correcting a phase demodulating error of an orthogonal frequency multichannel signal and belongs to the technical field of processing a communication signal. The method comprises the steps of: abstracting a phase value of each sub-carrier in a frame synchronous or training sequence code element, calculating a phase difference value of adjacent frame synchronous or training sequence code elements so as to calculate a phase average error value of each sub-carrier, calculating a phase deviation ratio according to the phase average error value and the position number of the frame synchronous or training sequence code element in an OFDM transmission frame, calculating a phase error compensation value of each sub-carrier of each symbol in the OFDM transmission frame according to the phase deviation ratio, and adding the phase error compensation value with a received instantaneous phase demodulating value of each OFDM symbol so as to obtain a compensatedphase value when the compensation phase error exists. The method has the advantages of estimating the phase deviation ratio by utilizing the known message in the OFDM signal frame structure, so as tosolve the problem of OFDM signal phase demodulating error under a condition of big constellation number.
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Description

Technical field

[0001] The invention relates to a method for correcting phase demodulation errors of orthogonal frequency division multiplex signals, and belongs to the technical field of communication signal processing. Background technique

[0002] Orthogonal Frequency Division Multiplexing (OFDM) technology has high spectrum utilization and good anti-multipath interference ability, suitable for high-speed multimedia data transmission, and has been successfully applied to digital audio broadcasting (DAB) and digital video broadcasting (DVB) In systems such as wireless local area network (WLAN) and asymmetric digital subscriber loop (ADSL), there are also good development prospects in the future mobile communication field. In an OFDM transmission system, an OFDM symbol is composed of multiple sub-carriers superimposed, and each sub-carrier is distinguished by orthogonality. The transceiver and the receiver adopt IFFT / FFT digital processing technology to realize the modulation an...

Examples

Embodiment Construction

[0035] The present invention will be further described in detail below with reference to the drawings and examples.

[0036] Take ADSL signal as an example, Figure 5 It is the frame structure diagram of the ADSL signal. The 69th symbol is the frame synchronization symbol, and the phase of each sub-carrier of this symbol is fixed. The number of sub-carriers of the ADSL signal is 256.

[0037] The position of the phase compensation part in the receiving system is as Image 6 As shown, for the frame synchronization symbols of several consecutive frames received at the receiving end, the phase demodulation value of each subcarrier of each frame synchronization symbol is recorded, because the data service of the ADSL signal only occupies a total of 250 from 6 to 255. Sub-carriers, let K=6, 8,...255 respectively, and obtain the average phase offset value Δθ of each sub-carrier of adjacent frame synchronization symbols by statistics 6 69 , Δθ 7 69 ,......,Δ 255 69 ,Use (1) to calculate ...