Learn More
—Mobile users' data rate and quality of service are limited by the fact that, within the duration of any given call, they experience severe variations in signal attenuation, thereby necessitating the use of some type of diversity. In this two-part paper, we propose a new form of spatial diversity, in which diversity gains are achieved via the cooperation of(More)
—This is the second in a two-part series of papers on a new form of spatial diversity, where diversity gains are achieved through the cooperation of mobile users. Part I described the user cooperation concept and proposed a cooperation strategy for a conventional code-division multiple-access (CDMA) system. Part II investigates the cooperation concept(More)
In this paper, we study a multiple antenna system where the transmitter is equipped with quantized information about instantaneous channel realizations. Assuming that the transmitter uses the quan-tized information for beamforming, we derive a universal lower bound on the outage probability for any finite set of beamformers. The universal lower bound(More)
—Millimeter wave (mmW) frequencies between 30 and 300 GHz are a new frontier for cellular communication that offers the promise of orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. This paper surveys measurements and capacity studies to assess this technology with a(More)
—With the severe spectrum shortage in conventional cellular bands, millimeter wave (mmW) frequencies between 30 and 300 GHz have been attracting growing attention as a possible candidate for next-generation micro-and picocellular wireless networks. The mmW bands offer orders of magnitude greater spectrum than current cellular allocations and enable very(More)
—We consider a general multiple-antenna network with multiple sources, multiple destinations, and multiple relays in terms of the diversity–multiplexing tradeoff (DMT). We examine several subcases of this most general problem taking into account the processing capability of the relays (half-duplex or full-du-plex), and the network geometry (clustered or(More)
—In this paper, an interference relay channel where two independent sources communicate with two destinations by the help of a relay is studied. The relay is full-duplex and employs decode-forward type strategy. Using Carleial's rate splitting where each source transmits common messages to be decoded at both destinations and private messages for the desired(More)
—We consider two interfering source-destination pairs that are assisted by a common relay. The relay simultaneously helps both sources to improve communication rates. We provide coding strategies that combine dirty paper coding, beamforming and interference reduction techniques at the relay and give an achievable rate region for Gaussian interference relay(More)
—We consider a cooperative transmission scheme in which the collaborating nodes may have multiple antennas. We present the performance analysis and design of space–time codes that are capable of achieving the full diversity provided by user cooperation. Our codes use the principle of overlays in time and space, and ensure that cooperation takes place as(More)