A wideband receiver AAGC method and device

Abstract

The application discloses a wideband receiver AAGC method, which obtains the radio frequency air interface power and the intermediate frequency statistical power after the ADC in the same statistical period, and obtains the change trend of the radio frequency air interface power; according to the change trend of the radio frequency air interface power, determines the starting point of the RF AAGC Control value; according to the relationship between the current radio frequency air interface power intensity, intermediate frequency statistical power intensity, and ADC saturation threshold, determine the current IF AAGC starting control value; perform overall uplink gain calculation, and make the RF AAGC and IF AAGC attenuation values ​​effective, and at the same time The digital field sets the compensation for the AAGC attenuation value. The application also discloses a wideband receiver analog AAGC device, which is characterized in that, by applying the technical solution disclosed in the application, the air interface power can be accurately measured in a large bandwidth / power range, and the start-up and control of the receiver can be greatly reduced ‑Release times, and has strong anti-blocking ability.

Description

technical field [0001] The present application relates to the field of communication technologies, and in particular to an AAGC method and device for a wideband receiver. Background technique [0002] In a communication system, due to factors such as fast channel fading, near-far effect of users, peak-to-valley ratio of modulated signals, multi-carrier superposition, and environmental interference, the power of the signal will cause rapid fluctuations in the signal strength received by the receiver, which has a large dynamic range. Therefore, the system generally adopts AAGC (analog automatic gain control) technology to absorb part of the fluctuation of the receiver signal, so as to reduce the dynamic range requirements of devices such as ADC (analog to digital converter). Generally, the AAGC algorithm determines the direction and step size of the analog channel gain adjustment in the next cycle through the difference between the preset target level and the RSSI (Received Si...

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Problems solved by technology

[0009] First, take the invention patent application with the application number 201180000313.1 as an example. It calculates the AAGC adjustment gain through the wideband and narrowband RSSI signal strength after the ADC. The problem that this technology cannot solve is: when the blocking signal and the useful signal overlap When entering the IF band and making the ADC input exceed the saturation threshold, due to the limited ADC bit width, the RSSI power after the ADC statistics at this time cannot accurately reflect the size of the air interface signal, so it is very likely that the correct attenuation cannot be calculated for the AAGC module. Amount, resulting in AAGC adjustment response lag, response speed decline, but also not conducive to the protection of the ADC device itself

[0010] Similarly, the patent application No. 201110060404.6 advances the power statistics of the first IF signal to the front of the IF filter and after the mixer, which seems to avoid the problem of ADC limitation, but it still cannot be solved. The interference signal falls into the RF front end, which will also cause blocking interference to the mixer and reduce the linearity, thereby distorting the useful signal and reducing the signal-to-noise ratio

[0011] Second, for non-long-term continuous intermittent burst interference, the current patented technology does not have a clear suppression algorithm. When the interference burst period is short, the high-response AAGC algorithm will instead introduce a large number of control and release actions. Causes frequent gain adjustments and affects the gain stability of the receiver link

[0012] Third, when there is carrier out-of-band blocking, the general AAGC method is to reduce the analog link gain and compress the ADC input signal. The consequence is that the in-band useful signal itself is also compressed by the AAGC algorithm, especially when the blocking is relatively high. When the useful signal is large but the useful signal is small, the useful signal strength after the control is compressed to be far away from the ADC saturation threshold, but the dynamic range of the ADC is not fully utilized

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