Method for channel estimation of wideband wireless mobile commutation system and channel estimator

Abstract

The invention discloses a method for channel estimation in a broadband wireless mobile communication system and a channel estimator. The method comprises the following steps: 1) pilot channel estimation is carried out by adopting a given algorithm to each pilot symbol in a plurality of pilot symbols transmitted by the channels, in pilot subcarriers within the usable subcarrier range, boundary value reprocessing is carried out to virtual pilot falling into the high frequency virtual subcarrier range so as to obtain the channel frequency response estimation of equal-interval pilot subcarrier position in a plurality of pilot symbols; 2) reverse Fourier transform is carried out to the channel frequency response estimation of the equal-interval pilot subcarrier position in a plurality of pilot symbols, so as to obtain time-domain channel impulse response estimation of a plurality of pilot symbols, and the time-domain channel impulse response estimation of the data symbol is obtained by adopting the given algorithm; and 3) after zero value insertion processing is carried out to a plurality of pilot symbols and the obtained time-domain channel impulse response estimation of the data symbol, the channel estimation result can be obtained by adopting the Fourier transform. The invention improves the accuracy and the robustness of the channel estimation.

Description

technical field [0001] The invention relates to the field of broadband wireless mobile communication systems, in particular to a channel estimation method and channel estimator in the broadband wireless mobile communication system. Background technique [0002] Broadband wireless mobile communication systems, such as Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) communication systems have the ability to resist interference between signals, and can provide high spectral efficiency to transmit signals, so they are regarded as the next generation of wireless mobile The transmission technology most likely to be used in the communication system has been widely used in many fields such as digital subscriber loop, digital audio / video broadcasting, wireless local area network and wireless metropolitan area network. On the other hand, the burst transmission mode based on packet switching is gradually replacing the continuous transmissio...

AI Technical Summary

Problems solved by technology

However, DFT interpolation requires the use of equally spaced pilot subcarriers across the entire frequency domain. In fact, the OFDM communication system contains virtual carriers (also called empty carriers) that cannot be used for data and pilot transmission. Among them, the low-frequency virtual carrier is used To eliminate the DC component of the signal carried by the channel, and the high-frequency virtual carrier provides a guard interval for the out-of-band leakage of the channel transmission signal, which will inevitably cause some pilot subcarriers to fall within the range of the virtual carrier, and then directly use DFT interpolation method will increase the error of channel estimation, especially in the subcarrier position near the virtual carrier

[0011] For the interpolation in the time domain, the weighted multi-slot averaging (WMSA, WeightedMulti-Slot Averaging) method can be used. Although WMSA interpolation can provide better interpolation performance under quasi-static channel conditions, its interpolation performance will decrease with the Doppler frequency shift f d，max Rapid deterioration of the increase, lack of robustness

[0012] In addition, the combination of different interpolation methods in frequency domain and time domain will also affect the performance of channel estimation

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