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Method for precisely estimating large frequency offset of DFT-s-OFDM (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing) system

An accurate estimation and SC-OFMA technology, which is applied in the field of large frequency offset estimation of discrete Fourier transform spread spectrum OFDM system, can solve the problem of automatic detection of resource blocks in the frequency domain, non-orthogonal subcarriers, Issues such as large uplink carrier leakage

Active Publication Date: 2015-06-03
BEIJING STARPOINT TECH COMPANY
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Problems solved by technology

[0003] The LTE uplink DFT-s-OFDM system uses a cyclic prefix (CP for short), which can overcome the ISI and ICI caused by multipath delay, but the baseband signal will cause intersymbol interference due to multipath effects and frequency selection characteristics. Not orthogonal to the subcarrier, the uplink carrier leakage is relatively large, which affects the demodulation performance of the receiver, specifically:
[0004] Because the DC component introduced by the transmitter will cause an impact signal at the zero frequency position of the signal, which will affect the automatic detection of resource block RB in the frequency domain; because the fluctuation of a single subcarrier is relatively large, and the interference of unallocated subcarriers is also Relatively large, which will affect the automatic detection of frequency domain allocation RB

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  • Method for precisely estimating large frequency offset of DFT-s-OFDM (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing) system
  • Method for precisely estimating large frequency offset of DFT-s-OFDM (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing) system
  • Method for precisely estimating large frequency offset of DFT-s-OFDM (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing) system

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[0076] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0077] figure 1 A schematic diagram showing the physical layer link process of the 3GPP DFT-s-OFDM system transmitter, figure 2 It shows the SC-FDMA time domain diagram in the DFT-s-OFDM system. In the existing 3rd Generation Partnership Project (3rd Generation Partnership Project, referred to as 3GPP) agreement, there are 7 symbols in one time ...

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Abstract

The invention provides a method for precisely estimating a large frequency offset of a DFT-s-OFDM (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing) system. The method comprises the following steps of synchronizing SC-OFMA (Single-Carrier Orthogonal Frequency Division Multiplexing) symbols; performing frequency offset estimation by utilization of a synchronized cyclic prefix CP and a data section tail part Tail so as to obtain a small frequency offset, and compensating the small frequency offset on a receiving signal; performing automatic RB (Resource Block) detection after removing the carrier leakage from the compensated receiving signal, and distributing sub carriers according to frequency domain RB so as to obtain a large frequency offset; generating a DMRS (Demodulation Reference Signal) local reference signal for a time slot under an unknown time slot number according to receiver DMRS symbols; obtaining a precise frequency offset according to an average phase difference of two DMRS symbols in one sub carrier, and obtaining a large frequency offset estimation range. According to the method for precisely estimating the large frequency offset of the DFT-s-OFDM system, the inter-symbol interference and the inter-sub carrier interference can be conquered, and the frequency offset estimation on signals is realized under the condition of unnecessarily knowing signal resource block allocation and sub frame sequence number in advance, so that the frequency offset range is enlarged, and the precision of the estimation result is improved.

Description

technical field [0001] The present invention relates to communication technology, in particular to a discrete Fourier transform spread spectrum orthogonal frequency division multiplexing (Direct Fourier Transformer Spread Orthogonal Frequency Division Multiplexing, referred to as DFT-s-OFDM) system large frequency offset estimation method. Background technique [0002] Time Division Long Term Evolution (TD-LTE) downlink adopts Orthogonal Frequency Division Multiplexing (OFDM) technology, and uplink adopts DFT-s-OFDM technology. The OFDM system has anti-symbol Both Inter Symbol Interference (ISI for short) and Inter-Carrier Interference (ICI for short) have the advantage of low peak-to-average ratio. [0003] The LTE uplink DFT-s-OFDM system uses a cyclic prefix (CP for short), which can overcome the ISI and ICI caused by multipath delay, but the baseband signal will cause intersymbol interference due to multipath effects and frequency selection characteristics. Not orthogon...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L25/03H04L25/02
Inventor 杨姗胡寒冰钱宇锋曹艳平
Owner BEIJING STARPOINT TECH COMPANY
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