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Blind frequency-offset estimation for temporally and/or spatially correlated signal

A frequency offset and signal technology, applied in the field of telecommunication systems, can solve problems such as phase information distortion

Inactive Publication Date: 2014-12-17
TELEFON AB LM ERICSSON (PUBL)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The spatial operations involved in such receivers are necessary for interference cancellation capabilities, but can also severely distort the phase information of the corresponding complex-valued signal

Method used

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  • Blind frequency-offset estimation for temporally and/or spatially correlated signal
  • Blind frequency-offset estimation for temporally and/or spatially correlated signal
  • Blind frequency-offset estimation for temporally and/or spatially correlated signal

Examples

Experimental program
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Embodiment Construction

[0017] The frequency offset estimation technique disclosed herein can be applied to any of the various multi-branch receiver architectures designed for various cellular systems, such as GSM / EDGE systems, single-carrier frequencies in 3GPP's Long Term Evolution (LTE) systems. Division Multiple Access (SC-FDMA) receivers or other Orthogonal Frequency Division Multiplexing (OFDM) based systems. Correspondingly, figure 1 A simplified block diagram of wireless system 100 including base station 110 and wireless transceiver 150 is shown. Base station 110 may comprise, for example, a GSM / EDGE base station or an LTE-evolved Node B, while wireless transceiver 150 includes a wireless radio configured to be compatible with one or more wireless standards and one or more frequency bands, including those supported by base station 110. receiver circuit and wireless transmitter circuit.

[0018] As shown, exemplary wireless transceiver 150 includes two receive antennas that provide a multi-d...

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PUM

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Abstract

An iterative, blind, frequency-offset estimation process that does not require any training signal or demodulated information symbols is disclosed. Receivers embodying the disclosed processes can produce periodic frequency-offset estimates, without running computationally intensive equalization or demodulation algorithms, by exploiting the temporal correlation of the received signal in the time domain, as well as the received signal's correlation across in-phase and quadrature dimensions, in some embodiments, to find a frequency-offset estimate that best fits the received signal in a maximum-likelihood sense. In an exemplary method of estimating receiver frequency offset, a temporally stacked signal block is formed from multi-branch signal samples corresponding to each of two or more time-separated samples of the received signal. The temporally stacked signal block is used in computing a maximum-likelihood joint estimate of the receiver frequency offset and the spatial covariance of the temporally stacked signal block de-rotated by the receiver frequency offset.

Description

technical field [0001] The present invention relates to telecommunication systems and, in particular, to methods and apparatus for estimating receiver frequency offset in wireless communication receivers. Background technique [0002] In a cellular communication system, a key task for a mobile terminal is to synchronize its internal reference time with the carrier frequency of the serving or other nearby base stations. Frequency synchronization is required not only to enable proper reception of radio signals transmitted from base stations, but also to ensure that the frequencies of radio signals transmitted from mobile terminals meet strict system specifications so as not to generate considerable interference to other users. [0003] In order to maintain a proper frequency reference for its oscillator, the mobile terminal typically performs periodic estimations of frequency offset, which is the deviation of the local reference signal from the actual frequency of the transmit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/00H04L27/26
CPCH04L27/2676H04L2027/0073H04L27/2671H04L2027/0053H04L27/2657H04B1/16H04L27/26
Inventor D·许
Owner TELEFON AB LM ERICSSON (PUBL)