CDMA is a multiple access technique to allow multiple users to share the same bandwidth, based on the orthogonality of their spreading codes. CDMA is a descendent of the direct sequence spread spectrum (DSSS) technology designed for antijam (AJ) and low probability of intercept (LPI) military systems. The spreading gain against jamming or detection is directly related to the ratio of the baseband signal to the spread signal bandwidth, so a spreading factor of 1000 can produce a 30 dB signal processing gain at a receiver that knows the spreading sequece. Frequency hopping is another military technology that can provide high levels of AJ protection. Rather than spreading the signal across all frequencies simultaneously, frequency hopping leaves the original signal bandwidth intact, but jumps from one operating frequency to another, hopefully faster than the jammer is capable of following. Contrast CDMA techniques with frequency hopping and conventional, single frequency systems from the perspective of transmitter and receiver design considerations.