VBaR: Content-sensitive variable GOP length scheme

In this paper, we propose a novel automatic gain control (AGC) algorithm as a solution to improve the signal reception performance based on the IEEE 802.15.4a chirp spread spectrum (CSS) over indoor fading channels. The CSS signals are composed of low-band and high-band signals whose frequency characteristics are different because of multipath fading in indoor environment. It is not appropriate to apply only one conventional AGC which regardless of the different bands, where the received signals are contaminated by quantization noise or clipped. The proposed AGC algorithm is based on two AGCs which are designed to be matched well with low-band and high-band signals separately.