Direct sequence CDMA for large meteor burst networks

The authors examine the application of direct-sequence random code-division multiple-access to large meteor-burst network. Narrowband meteor burst networks have succesfully supported networks of up to a few hundred nodes on a single channel by relying on the natural spatial multiplexing of the meteor channel to support communications. For large high-density meteor-burst networks, however, this spatial multiplexing can fail to provide adequate diversity to avoid collisions. A spread spectrum system can accommodate many thousands of nodes, and through a combination of channel propagation delay and the introduction of random time offsets operate with a single common spreading code. Throughput and waiting time predictions for such a system are illustrated as a function of the number of simultaneous users, network size, bandwidth, and signal level differences between users. It is shown that a spread spectrum system can accommodate very large networks and provide several orders of magnitude improvement over a conventional single channel system