Channel tracking for D-BLAST for airborne platforms

Coherent symbol detection requires knowledge of channel state information. The traditional use of embedding pilot symbols with payload data may not be easy to justify if channel variation is fast and/or the data rate requirement is high. We consider the implementation of the D-BLAST algorithm for airborne platforms and develop channel tracking schemes that eliminate or reduce the use of pilot symbols. In a normal operation mode, channel update is achieved dynamically as each layer of the D-Blast, encoded using an LDPC code, is decoded. We find the optimal symbol length to estimate a SISO channel under the Rayleigh channel model and then generalize it to the MIMO case. To ensure that the transceiver can detect outage due to the loss of channel state, an adaptive algorithm is devised utilizing the extremal property of the terminating likelihood ratio of an LDPC decoder.