All phase OFDM system design based on FPGA

Abstract

An OFDM (Orthogonal Frequency Division Multiplexing) is a key technology in the field of wireless communication, and a phase deviation is generated easily to cause restoration distortion of a carrier signal in a time-varying excitation environment, but FFT (Fast Fourier Transform) adopting an all phase signal preprocessing technology has phase invariability, and a research shows that an OFDM system utilizing the technology can reduce a phase error effectively, and can reduce the noise power significantly. According to the system, an all phase FFT processing unit for signal processing in the OFDM system can be achieved by adopting an FPGA (Field Programmable Gate Array) technology; an all phase processing module of the system is achieved by selecting a windowless all phase preprocessing method; an all phase OFDM baseband transmission system is achieved; the processing efficiency and the expense of an APOFDM (All Phase Orthogonal Frequency Division Multiplexing) system are simulated very well on hardware due to the parallelism and the dynamic reconstruction performance of an FPGA; the system has significant performance advantages, and is low in power consumption, high in integration level and good in stability; and therefore, the system has a better theoretical value and practical significance in further improvement of the OFDM system.

Description

technical field [0001] The present invention relates to a FPGA-based all-phase OFDM system design. OFDM is a multi-carrier transmission technology, which has the characteristics of high spectrum utilization efficiency, strong anti-symbol interference capability, and flexible modulation of carrier data rate, etc., and can be widely used. In signal processing, wireless communication, wireless transmission and other fields. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multi-carrier modulation technology, also known as Discrete Multi-Tone Modulation (DMT) in Asymmetric Digital Subscriber Line (ADSL). It uses inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT) to realize modulation and demodulation respectively, which is a multi-carrier modulation scheme with the lowest complexity and the widest application. Orthogonal frequency division multiplexing system adopts DFT transformation to realize the orthogo...

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Problems solved by technology

[0005] In order to solve the problem that the signal is prone to phase shift and cause carrier signal noise under the time-varying excitation environment, the FFT using the all-phase signal preprocessing technology has the characteristics of "phase invariance", and the windowless all-phase preprocessing method is selected to realize The all-phase processing module of this system, on the basis of the realized OFDM system, introduces the all-phase FFT processor based on FPGA into the OFDM baseband transmission system. The research shows that the OFDM system using this technology can effectively solve the phase error. Significantly reduces noise power

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