Loss formula for burst transmission spread spectrum systems

Abstract

In burst transmission spread spectrum systems it is advantageous to effect receiver synchronization by passive correlation, i.e. by matched filtering, and to detect the message by active correlation which means multiplication by a reference signal and integration in the time domain. If the number of available active correlation circuits is limited, a certain percentage of the arriving telegrams cannot be processed and will be lost. In conventional analog burst spread spectrum systems the loss can be calculated with the Erlang loss formula. For modern digital burst spread spectrum systems the Erlang loss formula is only an approximation which maiy give unaccurate results. In this paper an exact loss formula for digital spread spectrum systems will be presented and compared with the Erlang loss formula. The formula will be applied to minimize the loss of a practical system.