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Estimation method of integral multiple subcarrier frequency offset of robust

A carrier frequency offset and integer technology, which is applied to the estimation field of carrier frequency offset in OFDM communication system, can solve the problem of increasing the complexity of the estimation method, and achieve the effects of strong anti-multipath fading ability, simple implementation and large estimation range.

Inactive Publication Date: 2011-04-06
MAXSCEND TECH
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Problems solved by technology

However, considering that after the transmitted signal propagates through the channel, it will be affected by channel distortion in both amplitude and phase, so it is usually necessary to eliminate the adverse effects of the propagation channel before performing cross-correlation calculations to improve the accuracy of estimation, which increases the Estimate method implementation complexity

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  • Estimation method of integral multiple subcarrier frequency offset of robust

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Embodiment Construction

[0016] In the following description, the CMMB (China Mobile Multimedia Broadcasting) system is taken as an example for illustration. Two kinds of frequency-domain training sequences are defined in the CMMB standard: synchronization training symbols in beacon signals and frequency-domain pilot signals in normal OFDM symbols. The subcarrier mapping positions of these training sequences are known as well as the transmitted signal itself. Applying the method of the present invention based on the above two frequency domain training sequences can realize frequency offset estimation for integer multiples of subcarrier bandwidth.

[0017] The method of the present invention is described below using the synchronous training symbol in the beacon signal as the frequency domain training signal, which specifically includes the following steps:

[0018] Step 1, using the common FFT module in the OFDM system to realize the time-frequency domain transformation of the signal to obtain the rec...

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Abstract

The invention discloses an estimation method of integral multiple subcarrier frequency offset of a robust. In the method, by means of a known frequency domain training sequence in an orthogonal frequency division multiplexing (OFDM) system and the cross-correlation characteristic between a received signal and a known ideal signal, a channel frequency domain response is obtained by descrambling; and after time frequency domain conversion, an offset value of the integral multiple carrier frequency offset is judged according to the amplitude value of the obtained channel time domain pulse response. The estimation method can realize full multiplexing of a fast Fourier transform (FFT) module in the OFDM system and is slightly affected by multi-path channel attenuation; and the estimation method has the characteristics of simple implementation, high judgment accuracy and the like, thus being applicable to any OFDM communication system with the training sequence.

Description

technical field [0001] The invention relates to the field of digital communication, in particular to a method for estimating carrier frequency deviation in an OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) communication system. Background technique [0002] The OFDM system is widely used in broadband communication systems due to its high spectrum utilization rate and strong anti-multipath fading ability, especially for wireless broadband communication systems with variable propagation environments. At the same time, due to the technical characteristics of OFDM itself, OFDM modulation realizes the effective use of spectrum by parallelly modulating multiple mutually orthogonal sub-carrier signals in the effective frequency band, which causes the OFDM system to have an abnormal impact on carrier frequency deviation. sensitive. From the perspective of normalized subcarrier bandwidth, on the one hand, a carrier frequency deviation t...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L25/02
Inventor 程鑫豪沈潜朱华
Owner MAXSCEND TECH
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