Performance Evaluation of a Cooperative Diversity Enhanced Ad Hoc Network

This is a NAVAL POSTGRADUATE SCHOOL MONTEREY CA report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A450114. The abstract provided by the Pentagon follows: Currently wireless multi-hop ad hoc networks utilize protocols that relay packets of data node-by-node along a path connecting the source node to the sink node. This thesis describes a new methodology called "Cooperative Diversity" where information is relayed from the source to the sink via clusters of neighboring nodes. We first describe a routing protocol to establish spatially diversified paths through a field of randomly dispersed nodes. Second, an idealized configuration called the "Synthetic Waveguide" is introduced and its information theoretic channel capacity is developed. Third, we derive an outage model based channel capacity for the synthetic waveguide operating with a low forwarding latency. The low latency channel capacity is far different from that predicted by traditional channel capacity. Next, a simple modulation called stuttered simulcast is introduced and shown to approach the performance of an optimal distributed space-time code. Finally, a Monte Carlo simulation of the cooperative diversity routing protocol confines its superior performance in regions of operational interest.