Method for anti-self excitation of straight amplification station system

Abstract

The invention provides an anti-self-excitation method in a repeater system, and is applicable to the uplink and the downlink of a co-frequency wireless repeater. The method includes the following steps of: (1) taking a RF signal to be outputted in the coupling circuit in the uplink or the downlink in the repeater as a reference signal; (2) down converting the single in an affiliated link and the reference signal from a RF signal format to a baseband signal format; (3) eliminating the self-excitation element of the link signal in the affiliated link on the basis of the reference signal in the baseband level, for outputting a multi-carrier wave baseband signal of which the self-excitation interference signal is eliminated; (4) up converting the multi-carrier wave baseband signal into the RF signal and feeding the RF signal into the uplink or the downlink. The invention can cause the co-frequency wireless repeater to eliminate the self-excitation interference produced by the feedback signal effectively and adaptively, can lessen the requirement of the isolation degree of forward and backward antennas, can improve the gain of the system, can enlarge the coverage of the repeater, and is applicable for GSM / CDMA / CDMA2000 / WCDMA, and other systems.

Description

【Technical field】 [0001] The invention relates to the field of mobile communication, in particular to a repeater system anti-self-excitation method in same-frequency wireless repeaters. 【Background technique】 [0002] The same-frequency wireless repeater usually uses a duplexer to switch between the uplink and downlink, uses the forward antenna to receive the downlink signal of the base station, amplifies the useful signal through a low-noise amplifier, and then uses a narrowband filter to further filter the downlink signal with a power amplifier. The power is amplified and transmitted to the mobile station by the backward antenna; at the same time, the uplink signal of the mobile station is received by the backward antenna, and transmitted to the base station through a low noise amplifier, a narrowband filter, and a power amplifier. Its advantages are: to expand the coverage area at a cost far lower than the base station investment, the installation conditions are simple, a...

AI Technical Summary

Problems solved by technology

[0003] However, in practical applications, since the front and rear antennas of the same-frequency wireless repeater are installed near each other, coupling will inevitably occur. If the system gain is too large, it is greater than the isolation between the front and rear antennas of the repeater. , the repeater will have self-oscillation, causing the control channel of the base station to be blocked, and even cause the base station to be paralyzed

[0004]In the same-frequency wireless repeater system, the interference source formed by the feedback signal will lead to the decline of the performance of the receiver system, and then make the same-frequency wireless repeater The system gain of the station is usually about 10-15dB lower than the isolation between the transmitting antenna and the receiving antenna, which will affect the coverage of the repeater system

In order to increase the system gain of the same-frequency wireless repeater, it is necessary to increase the isolation between the transmitting and receiving antennas, which forms a contradiction with the above, and is usually difficult to achieve in engineering applications

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