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

CN101924730AInactive Publication Date: 2010-12-22BEIJING INSTITUTE OF TECHNOLOGYGY
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2010-12-22
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 compensated phase 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 to solve 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 the phase demodulation error of an OFDM signal, belonging to the technical field of communication signal processing. Background technique

[0002] Orthogonal Frequency Division Multiplexing (OFDM) technology has high spectrum efficiency and good anti-multipath interference ability, suitable for high-speed multimedia data transmission, and has been successfully applied in digital audio broadcasting (DAB) and digital video broadcasting (DVB) , wireless local area network (WLAN) and asymmetric digital subscriber loop (ADSL) and other systems, it also has a good development prospect in the future mobile communication field. In the OFDM transmission system, an OFDM symbol is composed of multiple subcarriers superimposed, each subcarrier is distinguished by orthogonality, and the transceiver and the receiver use IFFT / FFT digital processing technology to realize the modulation and demodulation of multi-carrier ...

Examples

Embodiment Construction

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

[0036] Take the ADSL signal as an example, Figure 5 is the frame structure diagram of the ADSL signal, in which the 69th symbol is a frame synchronization symbol, and the phase of each subcarrier of this symbol is fixed. The number of subcarriers of an ADSL signal is 256.

[0037] The position of the phase compensation part in the receiving system is as follows: Figure 6 As shown, the phase demodulation value of each subcarrier of each frame synchronization symbol is recorded at the receiving end for the frame synchronization symbols of several frames received continuously, because the data service of the ADSL signal only occupies a total of 250 subcarriers, then set K=6, 8, ... 255 respectively, and obtain the average phase offset value Δθ of each subcarrier of the adjacent frame synchronization symbol 6 69 , Δθ 7 69 ,...,Δθ 255 69 , u...