Parity bit selected spreading sequences: a block coding approach to spread spectrum

Parity bits are used to select the spreading sequence from a set of orthogonal spreading sequences, The information bits are then spread by this spreading sequence. At the receiver, the spreading code employed is determined from the outputs of the filters that are matched to each spreading sequence. The information bits are then determined from the output of the specific matched filter. Error correction is then performed by assuming that the parity bits are correct.