Semi-adaptive modulation and forward error correction for wideband communication systems

This paper presents a novel application of adaptive modulation and coding (AMC) for spacecraft communication systems. Whereas terrestrial AMC often assumes availability of either real-time or statistical channel state information at the transmitter (CSIT), in the space environment there are often insufficient resources to provide real-time access to channel statistics at the transmitter. We demonstrate a communication system architecture that utilizes some of the principles of closed loop AMC, but without the requirement of a feedback path to provide CSIT. We propose a system which switches among three modulation schemes commonly considered for implementation in the space environment: binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and 8-state phase shift keying (8-PSK). For these modulation states, we consider possible forward error correction algorithms which have been standardized by the Consultative Committee for Space Data Systems (CCSDS).