easily clas- sified, and from the jammer's point of view, hopefully are unpredictable by the receiver. The total energy Ej in the jamminig signal J(t) over the time interval (0, Ts) is given by (1.9) Obviously, the energy term involviong J9(t) serves no useful jamming pur- pose, and henceforth, will be assumed zero. (In keeping with this conserva- tive aspect of communication system design, we also assume that the jammer has full knowledge of timing and of the set {4;(t)} of basis functions.) The sum in (1.9) can be partitioned into K parts, the i-th part representing the energy used to jam the i-th receiver. Thus, (1.10) A Spread-Spectrum Overview A similar partition holds for the total transmitted signal energy Es, namely (1.11) Esi being the energy used by the i-th transmitter. The additive partitions (1.10), (1.11) are a direct result of the orthogonality requirement placed on the signals produced by the transmitter complex. The above signal representations and calculations have been made under the assumption that the channel is ideal, causing no attenuation, delay, or distortion in conveying the composite transmitted signal to the receiver com- plex, and that synchronous clocks are available at the transmitter and receiver for determining the time interval (0,Ts) of operation. Hence, impor- tant considerations have been suppressed in this initial discussion, SO that we may focus on one major issue facing both the communication system designer and the jammer designer, namely their allocations of transmitter energy and jammer energy over the K orthogonal communication links. 1.2 ENERGY ALLOCATION STRATEGIES Within the framework of an orthogonal communication system complex of multiplicity K, let's consider the communicator and jammer to use the fol- lowing strategies for allocating their available energies, Es and Ej respec- tively, to the K links. Communicators' strategy: Randomly select Ks links, Ks < K, for equal energy allocations, each receiving E&Ks units. The remaining links are not utilized. Jammer's s