Signal diversifying method for OFDM system

A signal and symbol technology, applied in the field of signal diversity of OFDM system, can solve the problems of transmission performance deterioration, achieve good promotion and application prospects, simple operation steps, and improve performance

Inactive Publication Date: 2009-03-25
BEIJING UNIV OF POSTS & TELECOMM
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Problems solved by technology

In the BICM algorithm, although the bit interleaving technology increases the time diversity of the coded modulation, the transmission performance of the scheme in the Gaussian channel becomes worse due to the decrease of the minimum Euclidean distance

Method used

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  • Signal diversifying method for OFDM system
  • Signal diversifying method for OFDM system
  • Signal diversifying method for OFDM system

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Embodiment Construction

[0023] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0024] see figure 1 , introduces the signal diversity method of the OFDM system of the present invention, which adopts OFDM technology and rotational modulation technology, obtains signal diversity gain by rotating the constellation diagram, and then improves the performance of the system.

[0025] Below in conjunction with accompanying drawing and applicant's implementation test, specifically illustrate each operation step of the inventive method:

[0026] Step 1. The sending end initializes the data: the sending end encodes and modulates the data block to be sent by each user according to the set encoding method and modulation method, and then performs modulation processing on the modulated data according to the set rotation angle. The block symbols are subject...

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Abstract

A signal diversity method of an OFDM system comprises the following steps: carrying out data decoding, modulation and rotation-modulation by a transmitting end, and storing the symbols of the processed data blocks; subjecting the symbols of the data blocks of a plurality of users in a memory to grouping and time-frequency interleaving, OFDM time-frequency resource allocation and Q-path interleaving according to the set number of the users, respectively subjecting the symbols of each data block to IFFT operation and CP addition after zero padding according to the OFDM modulation length, then transmitting the data; and subjecting the symbols of the data blocks to de-CP and FFT operations after a receiving end receives the data, carrying out phase compensation and zero removal, and sequentially subjecting the symbols of the obtained data blocks to Q-path de-interleaving, rotation demodulation, time-frequency de-interleaving and coding to obtain the desired data information. By adopting OFDM technique and rotation modulation technique and by selecting an optimal rotation angle, the method can acquire signal diversity gain and maximal performance improvement, thereby improving the system performance.

Description

technical field [0001] The present invention relates to a signal diversity method of an OFDM system, to be precise, relates to a simple and practical signal diversity method using rotational modulation and channel coding in an OFDM system, so that the time under fading channels can be well comprehensively utilized Diversity, frequency diversity, modulation diversity and channel coding gain reduce the frame error rate of the system, belonging to the technical field of diversity in data communication. Background technique [0002] Since Ungerboeck proposed Trellis Code Modulation (TCM) technology in 1982, coded modulation CM (Coded Modulation) technology has always been a hot research topic. The basic idea of ​​TCM is to comprehensively design the encoder and modulator as a unified whole, so that the encoded signal sequence generated by the cascaded encoder and modulator has the largest Euclidean free distance. Both the current theory and practice have shown that TCM can achi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L27/38H04L1/06H04L1/00
Inventor 吴湛击李璐颖王文博
Owner BEIJING UNIV OF POSTS & TELECOMM
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