J.C. Son

An enhanced packet scheduling algorithm combined with HARQ for HSDPA system

High speed downlink packet access (HSDPA) is a packet-based data service that supports downlink data rates of up to 14 Mbps in the WCDMA (wideband code division multiple access) system. In HSDPA, the packet scheduler is a key element for high-speed and efficient transmissions. In addition, hybrid automatic request (HARQ) plays a significant role in improving system performance. We propose an enhanced scheduling algorithm combined with HARQ to reduce transfer delay without the degradation of system throughput.

Enhanced Packet Scheduling Algorithm Providing QoS in High Speed Downlink Packet Access

In high speed downlink packet access (HSDPA), packet scheduler is a key element for high-speed and efficient transmissions. In this paper, we propose an enhanced packet scheduling algorithm which computes the priority according to the proportional fair algorithm. That is, for users to need hybrid ARQ retransmission in case of erroneous packets, the priority of the proportional fair algorithm is elegantly modified to reduce the transfer delay without degradation of system throughput.

Performance analysis of direct communication scheme in tactical radio access networks based on UMTS

In fast moving combat situations, the role of military wireless network is emphasized significantly. Over last decade, the civilian mobile communication technology has proceeded at an unprecedented pace. The advantages of civilian mobile communication technology, such as large capacity and reliable transmission, are attractive to the tactical communication network designers. As a result, lots of researches to apply the advantages of the civilian communications technology and architecture to designing the tactical communication systems have been investigated. Especially, the adaptation of the radio network subsystem (RNS) framework of Universal Mobile Telecommunication System (UMTS) for the tactical wireless communication system has been investigated. In this paper, we propose a new direct communication scheme in tactical radio access networks based on UMTS. The simulation results show the feasible performance when the direct communication scheme is applied in tactical radio access networks based on UMTS

Analysis of DS/SSMA system with hard-limiting correlator over fading channels with impulsive noise

The performance of a DS/SSMA (direct-sequence spread-spectrum multiaccess) system with hard-limiting correlation receivers is analyzed over nonselective Rician fading channels with impulsive noise. More specifically, computation of the average bit-error probabilities of the DS/SSMA system have been accomplished in this paper by exact computation for short spreading sequences and by approximation for long spreading sequences.<<ETX>>

Performance analysis of detectors in additive and multiplicative noise

Performance characteristics of the locally optimum detector for composite signals in additive and multiplicative noise are investigated. A noise model in which the effects of both additive and multiplicative noise components can simultaneously be considered for a signal detection problem is used. The signal is a composite which contains both deterministic and stochastic signal components. To illustrate the performance of the locally optimum detector, finite sample-size performance characteristics of the locally optimum detector are obtained and compared with those of other detectors.<<ETX>>