A fast Automatic Gain Control scheme for IEEE 802.15.4 receiver

The requirements for IC core based on IEEE 802.15.4 are fast computing and low complexity which challenge the traditional Automatic Gain Control (AGC) design. This paper presents a fast AGC scheme for IEEE 802.15.4 receiver, which can quickly accomplish gain adjustment in less than 1.5 symbols. Relating to numeric constant parameters determining the gain convergence speed and the number of samples beyond given thresholds, exponential non-linear adjustment functions are employed. For signals with large dynamic range, the proposed AGC scheme can adjust signals quickly and accurately. By achieving the full scale of Analog-to-Digital (A/D) converter, the proposed scheme can work well in low Signal-to-Noise Ratio (SNR) environment with low complexity.