Methods of Multiple Access Communications with Energy Detectors.
MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INFORMATION AND DECISION SYSTEMS
Pagination or Media Count:
For the infinite user population multiple access communication channel in which the number of colliding packets is known exactly, it has been shown previously that it is possible to achieve a throughput arbitrarily close to one. This result is examined. A particular two-step problem formulation is described. In this strategy, the time axis is divided into many small non-overlapping segments. By enabling subsets of this set of segments, collisions are generated to learn the number of data packets in each segment. In the second stage, each segment found to contain one or more data packets is resolved by splitting. It is shown that the problem of identifying the number of packets in each segment given the collision results is NP complete. A tradeoff between complexity and throughput is described. The number of packets in the backlog is lower bounded in terms of attainable throughput. The bound indicates that achieving high throughput requires an enormous amount of computation and very large delay, indicating that all strategies of this type are essentially useless for obtaining high throughput.
- Non-Radio Communications