A two-stage sequential demodulator for the Gosset lattice

A construction of the Gosset lattice is considered that has practical advantages over other constructions of the same lattice. Codes derived from this construction have been shown to exhibit a null at DC in their baseband spectrum. A two-stage approach to the demodulation of this construction of the Gosset lattice is discussed. This demodulator consists of an initial stage which may declare erasures and a secondary stage designed to correct erasures. A study of erasure events is made and then used to reduce the number of steps in the second-stage correction algorithm. While the overall demodulator is somewhat more complex than a straight forward maximum-likelihood demodulator designed for this construction, the present structure has the advantage of greater speed