Dragan Samardzija

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In this paper we develop a framework for competition of future operators likely to operate in a mixed commons/property-rights regime under the regulation of a spectrum policy server (SPS). The operators dynamically compete for customers as well as portions of available spectrum. The operators are charged by the SPS for the amount of bandwidth they use in(More)
In this paper, a multiple-input multiple-output (MIMO) extension for a third generation (3G) wireless system is described. The integration of MIMO concepts within the existing UMTS standard and the associated space-time RAKE receiver are explained. An analysis is followed by a description of an actual experimental MIMO transmitter and receiver architecture,(More)
In this paper we present multiple antenna transmitter optimization (i.e., spatial pre-filtering) schemes that are based on linear transformations and transmit power optimization (keeping average transmit power conserved). We consider the downlink of a wireless system with multiple transmit antennas at the base station and a number of mobile terminals (i.e.,(More)
In current wireless base station solutions it is becoming common to physically separate baseband units and radio subsystems. In many wireless technologies this architecture requires allocation of significant transport network resources. In this paper a low-latency baseband signal compression scheme is presented. The compression scheme significantly lowers(More)
The Centralized, Cooperative, Cloud Radio Access Network (C-RAN) is a next-generation wireless access network architecture based on centralized processing, collaborative radio, and real time cloud infrastructure. In this architecture, different access technologies (Global System for Mobile Communications (GSM)/Time Division Synchronous Code Division(More)
We analyze the effects of pilot assisted channel estimation on achievable data rates (lower bound on information capacity) over a frequency flat time-varying channel. Under a block-fading channel model, the effects of the estimation error are evaluated in the case of the estimates being available at the receiver only (open loop), and in the case when the(More)
We propose a channel state information (CSI) feedback scheme based on unquantized and uncoded (UQ-UC) transmission. We consider a system where a mobile terminal obtains the downlink CSI and feeds it back to the base station using an uplink feedback channel. If the downlink channel is an independent Rayleigh fading channel, then the CSI may be viewed as an(More)
In this paper we evaluate performance of the vertical BLAST (VBLAST) receiver algorithm in multipletransmitter/multiple-receiver (MTMR) cellular WCDMA systems. We assume that the VBLAST algorithm is executed on a symbol level (i.e, on the despreaded received signal), following a conventional bank of matched filters (correlators). Also, we introduce concept(More)
In systems employing coordinated base station transmission and reception (also known as network MIMO), information needs to be shared among clusters of coordinated bases. This information includes coherent channel state information, user data, and baseband received signals. The cost of leasing and maintaining a reliable backhaul to share this information(More)
We study the impact of higher-order sectorization (up to 12 sectors per cell site) in cellular networks with low angle spread and a high density of users. Under ideal sector patterns (with no intersector interference), the mean throughput per site scales directly with S, the number of sectors per site. Fixing the number of antennas per site to be 12,(More)