Adaptive error control coding for airborne communications

It is an important issue to design wireless communication and networking that radio resources should be efficiently utilized while providing guaranteed Quality of Service (QoS). In this area, link adaptation based on accurate channel quality estimation has attracted a lot of attention from both academia and industry. Topics such as power control, adaptive modulation and adaptive rate coding are under investigation. The basic idea of it is to adapt the transmitter in a packet to packet fashion. These works usually assume that channel quality estimation is available at the receiver and various delays are neglected. However, in some applications such as airborne transmission, channel quality estimation has to be considered. The challenge here is to estimate channel quality efficiently and accurately. In this work, we propose an adaptive error control coding scheme based on a novel channel quality estimator. The quality metric in design is packet Signal-to-Noise Ratio (SNR). We generate the estimate by re-encoding the decoder output and comparing with the hard decisions at the demodulator output. Adaptive rate transmission is achieved by using a Rate Compatible Punctured Convolution Code (RCPC). The code rate of the RCPC is selected to maximize the transmission throughput.