OFDM communication system and method based on companding

A companding, communication system technology, applied in transmission systems, multi-frequency code systems, digital transmission systems, etc., can solve problems such as constellation diffusion, reduce bit error rate, improve system reliability, and reduce constellation diffusion problems. Effect
CN103259758AActive Publication Date: 2013-08-21CHONGQING UNIV OF POSTS & TELECOMM
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Patent Information

Authority / Receiving Office
CN Β· China
Current Assignee / Owner
CHONGQING UNIV OF POSTS & TELECOMM
Publication Date
2013-08-21

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Abstract

The invention provides an OFDM communication system and method based on companding. A bit stream input into a transmitting device forms OFDM signals after base band mapping and IFFT, and after companding and transformation are carried out on the OFDM signals, parallel-serial conversion is carried out on the OFDM signals and then the OFDM signals enter a power amplifier, and the amplified signals are mapped to a transmitting unit to be transmitted; a receiving device carries out serial-parallel conversion on received time-domain signals, the first time of FFT is carried out on the time-domain signals, the time-domain signals is transformed into frequency domain signals, channel information is obtained through channel estimation, channel equalization is carried out on the received frequency domain signals, the equalized signals are converted into a time domain through the IFFT, expanding transformation is carried out on the equalized signals, then the equalized signals are sent to an FFT module for demodulation and decoding, and finally the needed bit stream is obtained through the base band mapping. The OFDM communication system based on the companding can effectively solve the problem that constellation diagrams of a traditional companding OFDM communication system are scattered in a multipath channel, can effectively reduce an EVM value, and lowers the error rate.
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Description

Technical field

[0001] The present invention relates to the field of communication technology, in particular to a communication system and method of OFDM (Orthogonal Frequency Multiplexing) technology. Background technique

[0002] The emergence of Orthogonal Frequency Division Multiplexing (OFDM) technology has solved the frequency selective fading of wireless channels and is considered to be one of the core technologies of the fourth-generation mobile communication 4G. One of the main shortcomings of the OFDM system is its large peak-to-average ratio (PAPR), which directly affects the operating cost and efficiency of the entire system. When the signal exceeds the dynamic range of the power amplifier and cannot be linearly input, it will cause serious signal distortion and destroy the orthogonality between the sub-carriers. Cause in-band signal distortion and out-of-band spectrum dispersion.

[0003] At present, many methods have been proposed to reduce the peak-to-average ratio...

Claims

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