Tianmin Ren

Learn More
— The use of smart antennas in extending coverage range and capacity of wireless networks dictates the employment of novel media access control protocols, with which the base station (BS) or access point (AP) provides access to users by learning their locations. We consider the class of protocols that employ beamforming and use contention-based or(More)
— We study the issue of handling unknown inter-cell interference in multi-cell environments with antenna arrays at the base stations. First, we demonstrate that the presence of unknown inter-cell interference that cannot be predicted accurately, can significantly degrade the system performance when unaccounted for. Second, we propose two algorithms that are(More)
— Recent advances in the area of wireless communications have revealed the emerging need for efficient wireless access in personal, local and wide area networks. Space division multiple access (SDMA) with smart antennas at the base station is recognized as a promising means of increasing system capacity and supporting rate-demanding services. However, the(More)
A b s u a b QoS provisioning to users in the presence of volatility of the wireless channel is the most challenging issue in wireless system design. In this paper, we consider the problem ofscheduling constant bit rate (CBR) traffic packets over the wireless channel, subject to packet delivery deadline eon-straints. We cast the problem as a Markov decision(More)
— We study the downlink scheduling problem in a cellular wireless network. The base stations are equipped with antenna arrays and can transmit to more than one mobile user at any time instant, provided the users are spatially separable. In previous work, an infinite traffic demand model is used to study the physical layer beamforming and power control(More)
  • 1