Method for estimating OFDM integer frequency shift based on virtual subcarrier and frequency domain differential sequence

A virtual subcarrier and integer frequency offset technology, applied in the field of communication, can solve the problems of narrowing the search range of frequency offset estimation, poor estimation performance, and low computational complexity.

Inactive Publication Date: 2007-04-18
SHANGHAI JIAO TONG UNIV +1
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Problems solved by technology

[0008] The purpose of the present invention is to provide a method for estimating OFDM integer frequency offsets in view of the disadvantages of poor estimation performance or high computational complexity in the prior art, which includes methods based on virtual subcarriers and frequency-domain differential sequences, and According to the ML (Maximum Likelihood, maximum likelihood) criterion, the OFDM integer frequency offset is estimated, and its performance is better than the method based on the virtual subcarrier and the method based on the frequency domain difference sequence. Offset pre-selected value, can narrow the search range of frequency offset estimation, with low computational complexity

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  • Method for estimating OFDM integer frequency shift based on virtual subcarrier and frequency domain differential sequence
  • Method for estimating OFDM integer frequency shift based on virtual subcarrier and frequency domain differential sequence
  • Method for estimating OFDM integer frequency shift based on virtual subcarrier and frequency domain differential sequence

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Embodiment Construction

[0113] A specific OFDM parameter configuration is given below to illustrate the implementation steps of the present invention. It should be noted that the parameters in the following examples do not affect the generality of the present invention.

[0114] Documents organized by 3GPP: TR 25.892 V6.0.0, "Feasibility Study for Orthogonal Frequency Division Multiplexing (OFDM) for UTRAN enhancement (Release6)" (Feasibility Study of OFDM Technology in Improved Universal Mobile Communication System and Terrestrial Radio Access Network ), a set of OFDM parameters is given, as follows:

[0115] Carrier frequency 2GHz

[0116] System bandwidth 6.528MHz

[0117] Number of subcarriers N 1024

[0118] Effective number of subcarriers N u 704(N u1 =N u2 =352)

[0119] Effective Bandwidth 4.495MHz

[0120] Subcarrier spacing f o 6.375kHz

[0121] cyclic prefix N g 64 points (9.803us)

[0122] Symbol period T 156.85+9.81=166.66us

...

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Abstract

The invention relates to a method for estimating OFDM integral frequency offset based on virtual subcarrier and frequency domain differential sequence, belonging to communication technical field. And the invention only need one OFDM symbol as synchronous training symbol in each frame, having advantage of low training sequence data overhead and the peak mean power ratio of the symbol is very small; the invention comprises methods based on virtual subcarrier and frequency domain differential sequence, and according to maximum-likelihood criterion, estimates OFDM integral frequency offset and has better performance than those of the methods based on virtual subcarrier and frequency domain differential sequence; in addition, the invention selects proper frequency offset preselected value and can reduce searching range of frequency offset estimation, thus having lower calculating complexity.

Description

technical field [0001] The present invention relates to a method in the technical field of communication, in particular to a method for estimating OFDM integer frequency offset based on a virtual subcarrier and a frequency domain difference sequence. Background technique [0002] At present, OFDM technology has been applied in more and more wired and wireless communication fields, mainly because OFDM technology has many advantages: effective resistance to multipath interference and narrowband interference, high spectrum utilization rate, and high data transmission rate. However, OFDM is very sensitive to synchronization deviation, especially to frequency deviation. The frequency deviation is further divided into a fractional frequency deviation of the subcarrier spacing and an integer multiple frequency deviation of the subcarrier spacing, which are hereinafter referred to as fractional frequency deviation and integer frequency deviation respectively. Among them, the fracti...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26
Inventor 丁铭罗汉文张霆蔚张际关韡佘锋
Owner SHANGHAI JIAO TONG UNIV
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