Method for estimating channel impulse response

Abstract

The invention provides an estimation method for channel impulse response, which is used in mobile communication system and including the following steps: (a) the channel impulse response is estimated initially h(i), i is equal to 0...N-1, (b) the energy of the N paths of the channel impulse response is calculated. The energy maximum is En Max and energy threshold value is En Max / T. T is more than 1. If the path energy in the channel impulse response is less than the energy threshold value, the path is set as a noise path and the channel impulse response value corresponding to the path is cleared, (c) channel impulse response estimation value h(i){i is equal to 0, ...L-1} is gotten to estimate noise variance according to different channel impulse response orders L. L ranges from Lstart to N. Lstart is an integer less than or equal to N, (d) the L value corresponding to the smallest noise variance is taken as the dispersion length M of the channel. The channel impulse response value from path M+1 to path N is cleared. Compared with the traditional method, the invention can inhibit the influence of noise on channel impulse response estimation and consequently improve balanced demodulation performance.

Description

technical field [0001] The invention belongs to the field of mobile communication, and in particular relates to a noise-suppressing channel impulse response estimation method suitable for an EDGE (Enhanced Datarates for GSM Evolution, Enhanced Datarates for GSM Evolution) system. Background technique [0002] GSM (Global System for Mobile Communications), as the second generation mobile cellular communication system, has been widely used all over the world. However, with the development of mobile communication technology and the diversification of services, people's demand for data services continues to increase. In order to provide a higher data communication rate in the existing GSM cellular system, the EDGE system introduces a multi-level digital modulation method - 8PSK (eight-phase phase-shift keying) modulation. Since 8PSK modulation maps 3 consecutive bits to one symbol of I / Q coordinates, it can provide higher bit rate and spectral efficiency. The EDGE system can p...

AI Technical Summary

Problems solved by technology

However, this invention only uses simple minimum L-M energy averages for noise estimation, which is likely to cause false deletion of channel impulse response due to error in noise energy estimation, thereby degrading the performance of equalized demodulation

In addition, the energy on each path is averaged first, and the tracking ability of the channel with a fast changing speed is insufficient.

[0008] The technical solutions of the above patents either do not take into account the impact of noise on the channel impulse response, or the computational complexity is relatively high, or it is difficult to accurately determine the actual dispersion length of the channel

Images