Method for using insertion pilot to inhibit phase noise in orthogonal frequency division multiplexing system

Abstract

The invention relates to a method using pilot frequency inserting to restrain the phase noise in the orthogonal frequency division multiplexing system, belonging to the transmission of digital information technical field. The method includes carrying the symbol mapping process at the transmitting terminal after the input signals are processed with scrambling code, channel encoding to generate the data symbols; obtaining the frame head; making up of the continuous pilot frequency composed of a pseudorandom sequence and guard gap, inserting the continuous pilot frequency into the data symbols, then processing disperse inverse Fourier transform to get the frame; multiple connecting the frame head and the frame to transmit after back end processing; processing frequency domain equilibrium using the estimated channel response at the receiving end, then carrying linear correlation on the poised signals and the pseudo random sequence to obtain the frequency domain estimated value of the phase noise; carrying disperse inverse Fourier transform on the frequency domain estimated value of the phase noise, than processing the phase correction on the received signals in the time domain to get the compensated signals. The computer simulation shows that the invention can effectively eliminate the phase noise interference with low arithmetic complexity and simple implement.

Description

technical field [0001] The invention relates to the technical field of digital information transmission, in particular to a method for suppressing phase noise by inserting pilots in an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique [0002] The main problem in the current digital information transmission technology (such as wireless transmission system) is how to effectively suppress the influence of phase noise on the signal during the signal transmission process. In high-speed wireless broadband transmission systems, high-order level modulation technology and OFDM technology are usually used simultaneously to improve spectrum utilization and counter channel frequency selectivity. However, the system using high-order level modulation is very sensitive to noise and radio frequency distortion. In addition, radio frequency distortion can easily destroy the orthogonality between subcarriers in the OFDM system, causing interference between subcarr...

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Problems solved by technology

[0020] Phase noise compensation technology based on DCT quadrature basis, see [R.A.Casas, S.L.Biracree, and A.E.Youtz.Time domain phase noise correction for OFDM signals.IEEE Trans.On Broadcasting, vol.48, no.3, pp.230 -236, 2002-9], but this method increases the computational complexity due to the large data when solving the LS equation

[0021] In addition, there are self-elimination methods that do not require compensation, see the literature [J.H Zhang, H.Rohlingnad, P.Zhang. Analysis of ICI Cancellation Seheme in OFDM Systems with Phase Noise. IEEE Transaction on Bordaeasting, June2004, Vol.50, 97-106] , but reduces the spectrum utilization due to the introduction of a large amount of redundancy

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