A Phase Noise Elimination Method of OFDM System Based on Orthogonal Polarization Transmission

Abstract

The invention discloses an OFDM system phase noise elimination method based on orthogonal polarization transmission, and belongs to the technical field of wireless communication. The OFDM system phase noise elimination method designs the transmitting terminal of an OFDM system, signals after traditional modulation are divided into two paths, conjugation is carried out in one path, and the signals are transmitted through an orthogonally polarized antenna after the orthogonally polarized states of the two paths of signals are given by the antenna; the signals are received through the orthogonal polarized antenna at a receiving terminal, after the conjugated signals are conjugated again, the two paths of signals are the same and are conjugated in phase noise, the two paths of signals are added, and then the imaginary part of the phase noise is eliminated, so that the phase noise item of multiplier interference can be approximate to 1, the influence of the phase noise on the received signals is eliminated, expected signals are obtained, and finally emit data information can be demodulated through a corresponding traditional demodulation method. The method solves the problems of high investment and price increment of terminal cost caused by the facts that the spectrum efficiency is low and a low phase noise local oscillator is redesigned in a self-elimination scheme.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to orthogonal polarization transmission technology and phase noise in OFDM system. Specifically, it refers to a phase noise elimination method of an OFDM system based on orthogonal polarization transmission. Background technique [0002] With the advent of the era of wireless broadband networks, orthogonal frequency division multiplexing (OFDM) technology has been widely used as an efficient multi-carrier technology. symbol interference (ISI) has better suppression performance, and has better robustness to the multipath effect caused by multi-carrier. However, in the OFDM system, the output of the local oscillator is not ideal due to noise and disturbance, and phase noise (PHN) will be generated, which will cause the common phase error (CPE) of the received signal subcarrier constellation of the OFDM system and the inter-subcarrier Interference (inter-channel interf...

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Problems solved by technology

These methods of suppressing CPE have their own deficiencies. For example, the LO hardware design requires more financial support, which will make the equipment more expensive; The additional overhead is to extract and process the information carried in the pilot frequency, which has a large delay and is not practical in high-speed communication; the decision-oriented compensation method depends on the correlation between symbols and is sensitive to decision errors, such as When the change is large, it will cause a large error and high complexity; the frequency spectrum of the self-cancellation method is only half of that of the OFDM system using traditional modulation, and there is a problem of extremely low spectral efficiency

Therefore, the PHN suppression and elimination technology in the existing OFDM system generally has the problems of high consumption and high complexity, and has obvious defects in practical applications, and is not universally applicable.

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