Spectrum sharing through receiver beacons in fading channels

Spectrum sharing through receiver beacons can obtain near-optimal sharing of spectrum between primary and secondary systems. Implementation of this in fading environment, however, requires a translation from interference constraint to the system- and device-level design parameters. Within the beacon-assisted spectrum sharing framework, the critical interference probability (CIP), defined as the probability of harmful interference to a primary receiver (PR) from a secondary transmitter (ST) located exactly at the PR´s protection bounds, serves as a lower limit of interference probability possibly experienced by the PR. By characterizing the CIP in terms of parameters as tolerable interference power of the PR, transmitted power of the beacon, beacon detection sensitivity of the ST, underlying propagation distribution as well as correlation measure between the beacon channel and the interference channel, the transmit power constraint mechanism of STs can be constructed for a given requirement for CIP. From the numerical results of CIP, it is noted that the frequency of a beacon channel should be selected carefully such that the propagation characteristics can be highly correlated with its indicating primary band.