Location-Probability-Based Transmission Strategy for White Space Devices With Multiple Antennas in TV White Space

Abstract

In the TV white space, geolocation database techniques are utilized to manage white space devices (WSDs) or secondary users' operations over the digital terrestrial TV (DTT) receiver protection, in which the location-specific maximum power of WSDs is calculated based on location probability. The multiple antennas can also be utilized for WSDs to protect the DTT receivers and simultaneously increase the WSDs' system performance. However, due to the lack of channel information at the transmitter, conventional multiple-antenna-based cognitive radio (CR) techniques cannot be applied to WSD transceivers. In this paper, we develop the transmission strategies for multiple-antenna-based WSDs operating on the geolocation database framework. We analyze the achievable throughput when the WSD receiver exploits zero-forcing (ZF) linear processing under imperfect channel estimation and, based on the analytic results, propose a dynamic WSD transmission strategy in which the number of active transmit antennas and the associated antenna indexes are determined according to the WSD operational parameters obtained from the geolocation database