Design and measurement results for cooperative spectrum sharing

Abstract

Scarcity of radio spectrum and inherent inefficiency of current spectrum allocation policies have spurred much research for alternative spectrum access techniques giving birth to the notion of cognitive radios.

Recently, cooperative spectrum sharing (CSS) where two wireless systems operate over the same spectrum band albeit with different priorities has been proposed as a viable framework for cognitive radio. However,

most of the proposed CSS protocols are interference limited and the performance of the systems are limited by the amount of interference from one system to another. Furthermore, most of the work on CSS can not

be validated due to lack of measurement results.

In this thesis, we try to resolve the above issues by proposing an interference-free CSS protocol known as orthogonal spectrum sharing scheme (OSSS) and as a proof-of-concept implement a CSS protocol on

a RF testbed. The performance of the testbed has been validated by obtaining both quantitative as well as qualitative results. Quantitative results are obtained by measuring the packet error rates for both primary and secondary systems whereas qualitative results are shown by utilizing a CSS protocol to successfully transmit two different images from PT to PR and ST to SR respectively.