Horizontal spectrum sharing and coexistence scenarios for mutually interfering wireless systems

Horizontal spectrum sharing occurs when multiple users share a given band of frequencies with no central control or coordination, and all users compete for access to the available spectrum. Depending on the actual approach used to allocate transmit power over available channels, mutual interference may affect user performance. Three types of horizontal spectrum sharing scenarios will be outlined in the paper, which can be reached through different user strategies for power allocation that can be more or less greedy in terms of channel use. The impact of such strategies for power allocation on user rates and total system throughput in dense and sparse spectrum sharing scenarios will be discussed in the paper. The discussion is illustrated with numerical results obtained from simulations, which show that less greedy approaches result in a more efficient spectrum sharing scenarios than the more greedy ones.