Self-adapted channel estimate device and its method based on CDMA frequency expansion sequence

Abstract

This invention relates to one self-adaptive signal channel estimation device based on CDMA extensive sequence and its method in communication signal process field, which comprises the following steps: the extensive signal generator makes two bit false random data sequence as input test signal and to give output signal through identification; second generator makes the same signals with the first one and to input it into self-adaptive filter; making even and variance values with probe parameter output signals as ones to be identificated.

Description

technical field [0001] The invention belongs to the signal processing field of mobile communication. Background technique [0002] The rapid growth of mobile communication technology and business has directly promoted the development of new generation wireless communication systems such as PCS (Personal Communication Service), Wireless LAN (Infinite Local Area Network), and Bluetooth (Bluetooth). This type of new wireless communication platform generally adopts microcell structure, that is, microcell and picocell in order to reduce the radius of the cell, improve the spectrum reuse rate, and increase the channel capacity. The basic characteristics of its wireless coverage are: (1) the channel propagation distance is short, and the mobile terminal is generally tens to hundreds of meters away from the base station; (2) the base station antenna is low, generally several meters to tens of meters; (3) the transmission The power is low, and the typical value of base station trans...

AI Technical Summary

Problems solved by technology

Since the configuration of micro cells and medium base stations is generally low, and the surrounding environment has a great influence on the field strength distribution, the propagation prediction model based on statistics and correction factors is no longer applicable

However, the ray tracing method requires consideration of the influence of multiple scattering, and usually can only analyze roads and buildings with simple geometric shapes, and there is a 4-8dB error with the measured value

Other commonly used channel test methods include direct radio frequency pulse method, frequency domain channel test method, etc., all of which require complex and expensive test equipment and complicated operation

The short-distance channel estimation method is mainly aimed at multi-carrier systems. There are estimation methods based on the IS-95 downlink pilot channel and multi-carrier system pilot symbols. Both methods need to insert Known symbols or sequences, extracting pilot symbols or sequences at the receiving end to estimate the impulse response of the channel, the disadvantage is that it occupies the channel bandwidth

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