Design and implementation of a new digital automatic gain control

Abstract

A new design method of an all-digital automatic gain control easy to implement is described and tested. The discretisation of the instantaneous gain provides a recursive form that merges the exponential function with the level detection. The first proposed circuit is well adapted for a software implementation. It comprises a simple control loop and two multipliers. It does neither contain digital filter nor divider and its setting only requires a loop gain parameter. Some tests were conducted on real digital audio signals with a dynamic range of 80 dB and they validate this approach. Under some conditions, the second circuit can even be simpler since it requires only one multiplier. It is well adapted to an field programmable gate array (FPGA) implementation for high speed signal processing.

A novel feed‐forward segmented digital automatic gain control algorithm for long‐term evolution digital radio‐over‐fibre systems

“…The simulation results indicate that FSD‐AGC algorithm is able to generate stable segmented gain for each power level to make full use of ADC quantisation bits width with stable PAR while avoiding oversaturation and it has a very fast reaction with short delay when segmentation signal power changes. While many existing AGC algorithms or circuits cannot adjust the signal quickly at the time when signal power changes, such as the digital AGC method proposed in [10] and AGC circuits realised in [20, 21]. Figs.…”

“…Figs. 8–10 show the AGC simulation results mentioned in [10, 20, 21], respectively, where the delay phenomenon is marked out by rectangular box. In some cases, they cannot successfully avoid overflow, as marked out by the circles in the second row of Figs.…”

“…Although the proposed AGC can be solved within 0.5 ms, it still cannot meet LTE requirement. In [10], an all‐digital AGC easy to implement with no level detector is proposed based on variable gain amplifier (VGA). It is optimised for fast processing architectures.…”

Efficient Implementation of Multichannel FM and T-DMB Repeater in FPGA with Automatic Gain Controller

“…A two-stage AGC algorithm for accurate gain adjustment was proposed in Reference [24], and Reference [25] proposed a new AGC method in which a simple digital algorithm-based implementation was successfully demonstrated without performance loss. More recently, Reference [26] proposed an all-digital AGC architecture without filter and divider.…”

Improving Metrological Properties of Electric Traction Energy Meters Using Fuzzy Controllers

“…The literature [12,13] provides a measurement system model to be used for amplification of the input signal of the ADC converter accordingly so that its entire dynamic range can be used. In order to select the appropriate value of the gain of the input signal to the analogue-digital converter, the corrector uses "the procedure of adaptation of parameters of the measurement system to parameters of the converted signals" [14].…”