Multiple Access with Time-Hopping Impulse Modulation

A time-hopping modulation format employing impulse signal technology has several features which may make it attractive for multiple-access communications. These features are outlined, an estimate of the multipleaccess capability of a communication system employing this format under ideal propagation conditions is presented, and emerging design issues are described. Time Hopping with Impulses The current emphasis on constant-envelope spread-spectrum modulations has caused engineers to ignore one design which has considerable potential, namely time-hopping. The technology for generating and receiving pulses on the order of a nanosecond or less in width, similar in shape to one cycle of a sine wave, is available. These monocycles can be received by correlation detection virtually at the antenna terminals, making a relatively low-cost receiver possible. A typical hopping format with pulse-position data modulation (PPM) is given by