Performance Analysis of Cellular Cdma in Presence of Beamforming and Soft Handoff (original) (raw)
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Performance of Data Services in Cellular CDMA in Presence of Soft handoff and Beamforming
2008
Performance analysis of data services is studied in CDMA network in presence of soft handoff (HO) and packet combining. Packet combining in conjunction with soft handoff is found to enhance throughput, reduce delay and packet delay variation (PDV) significantly. A stop and wait automatic repeat request (ARQ) scheme has been assumed. Two different packet combining schemes for packet data service, one based on log likelihood ratio (LLR) and another based on equal gain combining (EGC) have been studied. A cross layer interactions between ARQ and packet combining at link layer and soft HO in physical layer has been shown.
Forward Link Data Service with Beamforming and Soft Handoff in Cellular CDMA
Eng. Lett., 2009
The present paper proposes a scheme of combining soft handoff (HO) and beamforming in physical layer and automatic repeat request (ARQ) in link layer for improving the performance of data service in forward link of cell ular CDMA. A stop and wait ARQ scheme has been assumed for for ward link data service. Joint effects of beamforming and soft handoff via cross layer interaction reduce delay, bit error rat e (BER) and increase throughput significantly. Impacts of sever al parameters of soft handoff and beamforming and their cross lay er interaction on data performance have been evaluated . Both the cases of perfect and imperfect beamforming have bee n investigated. Effects of DoA (direction of arrival) estimation error associated with beamforming have also been in dicated on data service.
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/performance-of-data-services-in-cellular-cdma-in-presence-of-soft-handoff-beam-forming-and-packet-combining https://www.ijert.org/research/performance-of-data-services-in-cellular-cdma-in-presence-of-soft-handoff-beam-forming-and-packet-combining-IJERTV2IS100400.pdf Performance analysis of data services is studied in CDMA network in presence of packet combining, beam forming and soft handoff (HO). Beam forming in conjunction with soft handoff and packet combining is found to enhance throughput and reduce delay and BER significantly. It also reduces packet delay variation (PDV) significantly. Both the cases of perfect and imperfect Beam forming are investigated. Two different packet combining schemes for packet data service, one based on log likelihood ratio (LLR) and another based on equal gain combining (EGC) have been studied. A cross layer interactions between ARQ and packet combining at link layer and soft HO and beam forming in physical layer has been shown. Truncated automatic repeat request (T-ARQ) is used at link layer to satisfy a prescribed delay constraint. The impact of processing gain, number of retransmissions, throughput, delay and packet loss on system performance is studied.
Effects of multicell beamforming on downlink data services in cellular CDMA
International Journal of Communication Networks and Distributed Systems, 2010
This paper proposes and evaluates a scheme of combining multicell beamforming, power control, soft handoff in physical layer and automatic repeat request (ARQ) in link layer for improving the performance of data service in forward link of cellular CDMA. The present paper also proposes a scheme of beamforming-based power control scheme in physical layer for forward link of cellular CDMA. Beamforming has been assumed at three base stations (BSs) in our system model. A stop and wait ARQ scheme has been assumed for forward link data service. Joint effects of beamforming, power control, number of retransmission and soft handoff via cross-layer interaction reduce delay, bit error rate (BER) and increase throughput significantly. Impacts of several parameters of soft handoff, power control and beamforming and their cross-layer interaction on data performance have been evaluated. Both the cases of perfect and imperfect beamforming have been investigated. Effects of direction of arrival (DOA) estimation error associated with beamforming have also been indicated on data service.
FORWARD LINK PERFORMANCE OF PACKET DATA IN PRESENCE OF SOFT HANDOFF IN CELLULAR CDMA
— Effects of soft handoff (HO) on forward link performance of packet data service have been presented in this paper. Outage of packet data transmission using Code Division Multiple Access (CDMA) is evaluated. Throughput and delay have also been investigated in Cellular CDMA in presence of soft HO. Influence of physical layer issues like soft HO parameters, shadowing correlation, power control error(pce) on packet data performance in forward link has been investigated.
Int'l J. of Communications, Network and System Sciences, 2009
An adaptive data transmission scheme based on variable spreading gain (VSG) is studied in cellular CDMA network in presence of soft handoff (HO). The processing gain is varied according to traffic intensity meeting a requirement on data bit error rate (BER). The overall performance improvement due to processing gain adaptation and soft HO is evaluated and compared with a fixed rate system. The influence of soft HO parameters on rate adaptation and throughput and delay performance of data is indicated. Further truncated automatic repeat request (T-ARQ) is used in link layer to improve the performance of delay sensitive services. The joint impact of VSG based transmission in presence of soft handoff at physical layer and T-ARQ at link layer is evaluated. A variable packet size scheme is also studied to meet a constraint on packet loss.
Design and Performance Analysis of a New Soft Handoff Scheme for CDMA Cellular Systems
IEEE Transactions on Vehicular Technology, 2006
In this paper, a new soft handoff scheme for CDMA cellular systems is proposed and investigated. It is pointed out that some handoff calls unnecessarily occupy multiple channels with little contribution to the performance of handoffs in IS95/CDMA2000-based handoff schemes or systems. To alleviate performance degradation due to channel resource shortage during soft handoff, a new concept of channel convertible set (CCS), which contains several types of handoff calls that unnecessarily occupy extra channels by considering the relative mobility of the calls in the handoff area is introduced. A new scheme that reallocates those extra channels in the CCS to new handoff calls when there is no available free channel in the system is proposed. Furthermore, according to the variation of the CCS, the proposed scheme dynamically adjusts the number of guard channels reserved exclusively for handoff. Then, the feasibility and implementation issues of the proposed scheme are discussed. To evaluate and compare performance indexes of different soft handoff schemes, continuous-time Markov chain models are constructed. Automated generation and solution of the underlying Markov chains are facilitated by stochastic reward net models, which are specified and solved by stochastic Petri net package. Numerical results show that this scheme can significantly decrease both the number of dropped handoff calls and the number of blocked calls without degrading the quality of communication service and the soft handoff process.
Performance analysis of soft handoff in CDMA cellular networks
2001
A unique feature of code division multiple access (CDMA) systems is the use of soft handoff between cells. Soft handoff, in general, increases the system capacity because while the link between a mobile and one base station is poor, it might be better between the same mobile and some other base station. Hence, the user may transmit at a lower power in a soft handoff situation. Teletraffic analysis of soft handoff is complex because one cannot separate transmission issues from traffic issues. Many papers in the literature have independently analyzed the effect of soft capacity and soft handoff on network performance. Some papers have analyzed the effect of soft handoff on soft capacity but there has been no proper teletraffic analysis that includes both soft capacity and soft handoff. This paper proposes a traffic model for a DS-CDMA cellular network that includes both soft capacity and soft handoff. Network performance is then computed in terms of call blocking.