Coding of spread spectrum signals for HF communications

Problems connected with HF communications are atmospheric noise, multipath propagation and interfering signals from other users. In military applications also intentional jamming should be considered. A method used to cope with these problems is wideband transmission combined with coding techniques. We investigate and compare the efficiency of coding applied in two well-known wideband techniques; direct sequence (DS) signaling, and orthogonal frequency division multiplexing (OFDM) or multicarrier transmission. We let the channel be disturbed by both Gaussian noise and narrowband interfering signals according to the Laycock-Gott (1988) model