A Cost Model for Communication in the Presence of Interference

This paper develops a model for determining what values of bandwidth, total transmission time and average power to assign to a simple communication system so as to get a message transmitted through interference at minimum cost. Also, for given values of average power, the question is examined as to whether it is best to send single pulses with high peak power or repeat many smaller pulses of lower peak power. The communication system discussed is binary where a "1" will be represented by a positive pulse and a "0" by a negative pulse. It will be assumed that all possible messages that can be sent (namely M) have been listed and given a binary number. Therefore, in order to be able to identify a particular message we must send N bits (N log2 M). The main assumptions of the model are: 1) Only pure repetition is allowed for redundancy. 2) If one bit is missed, then the entire message is lost. 3) The interference power at the receiver is known and constant with respect to the message power at the receiver.