OFDM (orthogonal frequency division multiplexing) channel estimation method based on symmetrical basis expansion model for quick time-varying channel

Abstract

The invention discloses an OFDM (orthogonal frequency division multiplexing) channel estimation method based on a symmetrical basis expansion model for a quick time-varying channel, and provides an estimation method for the quick time-varying channel. Under complex channel environments of high speed, medium speed, low speed and the like, existing channel estimation methods based on the basis expansion model have poor robust feature. Channel estimation based on the symmetrical basis expansion model is provided. A pilot frequency symbol Y(p) is extracted from a frequency domain receipt signal Y(k). According to the pilot frequency symbol Y(p), a basis coefficient vector corresponding to channel multipath time-domain impact response is estimated by the symmetrical basis expansion channel model. According to the coefficient vector, a time-domain channel matrix is calculated, so that the channel impact response is acquired, and channel estimation is completed. The method is low in complexity, and is a novel high-precision estimation method for the quick time-varying channel. The method can be used in various communication systems adopting OFDM to modulate so as to estimate the channel, and can also be used in a code division multiple access (CDMA) system and a time division multiple access (TDMA) system so as to estimate the channel.

Description

Technical field [0001] This patent invents a fast time-varying channel estimation method based on a symmetric base spreading model applied in an OFDM system, which belongs to the field of wireless communication, and particularly relates to an OFDM channel estimation method that belongs to the digital mobile communication field of practical electromagnetic wave technology. Specially designed digital terrestrial television, single-carrier OFDM communication system, multi-carrier communication system, wireless local area network (WLAN) and other digital communication systems using OFDM modulation channel estimation technology. At the same time, the present invention can not only perform channel estimation in code division multiple access (CDMA) systems and time division multiple access (TDMA) systems, but the idea of ​​the present invention can also be used in all BEM methods and its derivative methods for estimating radar, remote control and telemetry, Other characteristic paramet...

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Problems solved by technology

[0024] Aiming at the existing fast channel estimation method, which does not have good robustness in the complex channel environment, and there are large errors in the estimation of the channel edge, the present invention proposes a method based on symmetric base extension applied in the OFDM system The model's fast time-varying channel estimation method, which reduces the number of estimated parameters, reduces the computational complexity, reduces the bit error rate of existing channel estimation, and can effectively solve the channel estimation problem in complex channel environments

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