Realization method of fpga based on threshold vector circle ofdm signal direct clipping technique

Abstract

The invention belongs to the technical field of signal processing and communication systems, and discloses an FPGA implementation method based on the threshold vector circle OFDM signal direct clipping technology; the method of using a lookup table is used to realize direct clipping on the FPGA hardware platform, and the pre-calculated threshold The coordinates on the vector circle are stored in the ROM of the FPGA, and the ROM address is determined according to the tangent value of the signal phase, which reduces the computational complexity and reduces the delay at the sending end of the OFDM system under the premise of ensuring that the PAPR meets the index requirements, and only exists The quantization error of a table lookup. The invention only stores points on one-eighth of the vector circle, and other parts are obtained through triangular transformation, thereby reducing the use of ROM resources in the FPGA. The invention is applied to any communication system developed on the FPGA platform and using the OFDM transmission mode, and realizes the direct amplitude limitation of the signal under a small system overhead, so as to reduce the PAPR.

Description

technical field [0001] The invention belongs to the technical field of signal processing and communication systems, and in particular relates to an FPGA implementation method based on threshold vector circle OFDM signal direct clipping technology. Background technique [0002] At present, the existing technology commonly used in the industry is as follows: OFDM is Orthogonal Frequency Division Multiplexing technology, which is a kind of multi-carrier modulation. The main idea is to divide the channel into several orthogonal sub-channels, convert high-speed data signals into parallel low-speed sub-data streams, and modulate them for transmission on each sub-channel. Orthogonal signals can be separated by using correlation techniques at the receiver, which can reduce the mutual interference (ISI) between subchannels. The signal bandwidth on each subchannel is smaller than the relevant bandwidth of the channel, so each subchannel can be regarded as flat fading, which can elimi...

AI Technical Summary

Problems solved by technology

[0004] (1) The signal predistortion algorithm will introduce distortion;

[0005] (2) Coding algorithms will reduce the frequency band utilization;

[0006] (3) Probabilistic algorithms will increase the complexity of the system

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