Closed loop automatic level control method and apparatus for TDD mode communicating system

Abstract

Disclosed are a closed loop automatic level control method and a device used for the TDD mode communication system. The method is that during the coupling process of the input radio-frequency signal which is processed with radio-frequency coupling, radio-frequency attenuation and power amplification firstly, the input signal is detected in advance to extract the signal envelope for the voltage comparator of a singlechip and the signal envelop is compared with the preset voltage value to obtain the synchronous signal time sequence; then the level of the output signal is detected and is transmitted to the A / D converter of the singlechip; the A / D converter of the singlechip samples and outputs the detection signal; the singlechip judges the signal level; then the radio-frequency attenuator in the link circuit is controlled by the singlechip to realize the stable closed loop automatic level control. The device comprises a serial connection of a first radio-frequency coupler (7), a radio-frequency switch (1), a radio-frequency attenuator (2), a drive amplifier (3), a power amplifier (4) and a second radio-frequency coupler (8); the control end of the radio-frequency attenuator (2) is connected with a singlechip (9) in which a voltage comparator and an A / D converter are imbedded; the output ends of the first and second radio-frequency couplers (7, 8) are respectively connected with first and second radio detectors (5, 6); the first radio detector (5) is connected with the input end of the voltage comparator of the singlechip; the outputted signal of the second radio detector (6) is connected with the input end of the A / D converter of the singlechip; the output end of the singlechip (9) is connected with the control end of the radio-frequency switch (1).

Description

technical field [0001] The invention belongs to the field of wireless communication, and in particular relates to a closed-loop automatic level control method for a TDD mode communication system and a realization device thereof. Background technique [0002] At present, the FDD mode dominates the world in the first generation and second generation mobile communication systems, and the TDD mode has not attracted attention. Due to the needs of new business and the development of new technologies, as well as many advantages of the TDD model, the TDD model will be increasingly valued. Time Division Duplex (TDD) is a duplex mode of a communication system, which is used to separate receiving and sending channels in a mobile communication system. TDD mode communication systems such as WLAN, WIMAX, and TD-SCDMA are developing and applying at a high speed. In the past, TDD mainly used base station equipment to implement closed-loop automatic level control. This method required the ...

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