Method and system for efficiently restraining large peak-to-average power ratio (PAPR) of OFDM system based on companding

Abstract

The invention discloses a method and a system for efficiently restraining large PAPR of OFDM system based on companding, wherein the PAPR is debased and the error rate is reduced. The invention is characterized in that the invention provides a companding method for reducing the probability of generating large PAPR based on hyperbolic asymptote companding function by analyzing the fundamental reasons to the PAPR problem in the OFDM system and the factors of generating low probability of large PAPR, starting compressing time-domain large signal, enlarging time-domain dwarf signal and limiting super-large signal in combination with the advantages of amplitude limiting and companding. The invention is applied to OFDM system.

Description

technical field [0001] The invention relates to the problem of peak-to-average power ratio in an OFDM communication system, in particular to a nonlinear companding method and system for effectively suppressing a large peak-to-average power ratio of the OFDM system. Background technique [0002] Orthogonal frequency division multiplexing OFDM technology is considered to be one of the core technologies of the fourth generation mobile communication 4G because of its efficient spectrum utilization and good anti-multipath fading performance. At present, OFDM technology has been used in asymmetric digital subscriber line ADSL , digital audio broadcasting DAB and digital TV broadcasting DVB, IEEE 802.11, IEEE 802.16 and power line broadband data communication have been widely used. [0003] The basic principle of OFDM is to distribute high-speed data streams to several sub-channels with relatively low transmission rates for transmission through serial-to-parallel conversion. Since...

AI Technical Summary

Problems solved by technology

As μ increases, this improvement becomes more and more obvious, but due to the companding curve characteristics of the traditional companding transformation function, it is not enough for the compression of very large signals and the expansion of very small signals, so the data symbols after companding transformation cannot presents a uniform and tight distribution

Although the inverse companding transform can basically restore the received signal, because the average power of OFDM symbols will be slightly different, there will be some differences between the signal after companding and inverse transforming and the original signal, that is, the companding transform will cause certain BER

[0024] It can be seen that although the companding transformation is more flexible than the clipping, the companding transformation needs to be further improved in suppressing the generation of large PAPR, improving the distribution of OFDM symbols and improving the bit error rate

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