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Demodulating method and system of space frequency coding of OFDM system

A technology of space-frequency coding and transmit diversity, which is applied to multi-frequency code systems and prevents/detects errors through diversity reception, which can solve problems such as receiver performance degradation and achieve the effect of overcoming performance degradation

Inactive Publication Date: 2010-02-17
TSINGHUA UNIV
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Problems solved by technology

[0007] The purpose of the present invention is to provide a solution to the OFDM system space-frequency coding transmit diversity that can overcome the defect that the performance of the receiver is degraded due to the large fluctuations in the frequency response between adjacent subcarriers when using traditional orthogonal inverse matrix decoding tuning method and system

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  • Demodulating method and system of space frequency coding of OFDM system
  • Demodulating method and system of space frequency coding of OFDM system
  • Demodulating method and system of space frequency coding of OFDM system

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Embodiment Construction

[0037] The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0038] The transmit diversity method of this embodiment is applied to a receiver for receiving space-frequency codes, figure 1 It is a structural block diagram of the system transmitter using space-frequency coded OFDM, such as figure 1 As shown, the input signal can be a bit stream that has been channel-coded or not channel-coded. After symbol mapping, it is mapped into symbols and then constitutes an OFDM frame. Each OFDM frame is input into the space-frequency coding module to obtain two outputs (because in this There are two diversity antennas in the embodiment), the space-frequency coding method includes but not limited to the following methods:

[0039] The first o...

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Abstract

The invention discloses transmit diversity demodulating method and system of space frequency coding of an OFDM system. The method comprises the following steps: converting the received radio frequencysignal into a baseband signal; carrying out evaluation on timing frequency deviation and carrier frequency deviation on the baseband signal to obtain a timing frequency deviation evaluation value anda carrier frequency deviation evaluation value of the baseband signal; according to the timing frequency deviation evaluation value and the carrier frequency deviation evaluation value, carrying outthe correction on timing frequency deviation and carrier frequency deviation on the baseband signal to obtain each corrected baseband signal; according to each corrected baseband signal, solving the signal channel frequency range response of each diversity antenna; and carrying out the space frequency decoding by utilizing a nonorthogonal inverse matrix. The invention completes the space frequencydecoding by using a new decoding matrix, thereby solving the problem that the property is reduced because large frequency response fluctuation is generated between neighboring subcarriers when an orthogonal inverse matrix is traditionally used for decoding.

Description

technical field [0001] The invention relates to the technical field of mobile signal reception, in particular to a demodulation method and system for space-frequency coding transmit diversity of an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique [0002] Different channel environments will be encountered in broadband wireless transmission, and in many areas, especially in urban areas, the interference is very serious. increase. The use of equalization technology is no longer enough to combat the time-varying fading and multipath interference experienced by digital multimedia signals during transmission. In order to combat greater time-varying fading and multipath interference, diversity technology is usually used. Diversity technology is an effective technology to overcome channel fading. It transmits the same information separately through several unrelated fading channels to generate multiple copies, and then extracts useful signals from the...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L1/06H04L27/26
Inventor 王劲涛雷伟龙王军潘长勇宋健杨知行
Owner TSINGHUA UNIV
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