Spread spectrum communication networks
Abstract
One of the difficulties that arises in the analysis of codeword and packet error probabilities in asynchronous frequencyhop (FH) multipleaccess communication systems and networks is the statistical dependence between symbol errors within a codeword or packet in FH communications with multiple symbols per dwell interval. The basic problem is that the hits by other transmissions are statistically dependent. In one paper, we developed improved bounds on the codeword error probability for such FH multipleaccess systems and networks. This was accomplished by investigating models in which hits are conditionally independent given the number of interfering packets and choosing the conditional probability of a hit in such a way that a bound on the performance of the actual system can be obtained. We showed that if the ratio of the number of interfering packets to the number of frequency slots is held constant, hits the asynchronous FH networks are asymptotically independent in the limits as the number of frequency slots increases. Thus, when the number of frequency slots is large, the error probabilities can be closely approximated by using the simplified model with independent hits. We published a related paper which shows that, contrary to a paper published by another author, the sequence of hits in an asynchronous FH multipleaccess communication system does not form a Markov process.
 Publication:

Final Report
 Pub Date:
 February 1991
 Bibcode:
 1991uill.rept.....P
 Keywords:

 Communication Networks;
 Markov Processes;
 Multiple Access;
 Probability Theory;
 Spread Spectrum Transmission;
 Error Analysis;
 Frequency Hopping;
 Packets (Communication);
 Synchronism;
 Telecommunication;
 Communications and Radar