Diversity Combining (DC) and multipacket detection (MPD) are efficient techniques that cope with packet errors due to severe propagation conditions and/or collisions. To evaluate their network performance on a network...
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Diversity Combining (DC) and multipacket detection (MPD) are efficient techniques that cope with packet errors due to severe propagation conditions and/or collisions. To evaluate their network performance on a network simulator, an accurate characterization of the Bit Error Rate (BER) and Packet Error Rate (PER) can successfully replace the behavior of the PHY layer. This choice is better in terms of computational time than implementing a full PHY layer to be jointly simulated with the upper layers. In this paper, an analytical model is proposed to compute the BER and PER of DC, MPD and hybrid techniques, considering a Single-Carrier with Frequency-Domain Equalization (SC-FDE) scenario. The paper also considers two frequency-domain detection methods: a simple linear receiver and a powerful iterative receiver. The proposed model is simple and versatile, since it can support nonhomogeneous transmitting powers, and different channel conditions concerning retransmissions and channel randomization techniques. Several simulations show that the proposed model provides accurate BER and PER results for a wide range of scenarios.
Traditionally, a packet with errors, either due to channel noise or collisions, is discarded and needs to be retransmitted, leading to performance losses. Two different approaches are considered to cope with lost pack...
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ISBN:
(纸本)9781424483310
Traditionally, a packet with errors, either due to channel noise or collisions, is discarded and needs to be retransmitted, leading to performance losses. Two different approaches are considered to cope with lost packets, a low-complexity packet combining ARQ scheme (Automatic Repeat reQuest) and a multipacket detection scheme. These approaches are employed on a SC-FDE scheme (Single-Carrier with Frequency Domain Equalization). Suitable receiver structures are described, employing packet combining, multipacket detection and hybrid schemes. An accurate analytical tool is presented for predicting the performance of the different schemes.(1)
multipacket Reception (MPR) techniques employing either Direct Sequence Code Division Multiple Access (DS-CDMA) or Network Diversity Multiple Access (NDMA) have great potential to deal with packet collisions from mult...
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ISBN:
(纸本)9781467318792
multipacket Reception (MPR) techniques employing either Direct Sequence Code Division Multiple Access (DS-CDMA) or Network Diversity Multiple Access (NDMA) have great potential to deal with packet collisions from multiple Mobile Terminals (MTs). However, their performance evaluation in practical systems is difficult because lengthy simulations are needed to obtain the packet error rates for specific channel conditions. This paper considers MPR receivers based on the Iterative Block Decision Feedback Equalization (IB-DFE) concept. An analytical tool that computes the Bit Error Rate (BER) and Packet Error Rate (PER) for DS-CDMA is proposed, where its theoretical results have a good accuracy. This analytical approach, that provides a simple and relatively fast way to compute the BER and PER performance for DS-CDMA, is then employed for a comparison with NDMA. (1)
Traditionally, a packet with errors, either due to channel noise or collisions, is discarded and needs to be retransmitted, leading to performance losses. Hybrid Automatic Retransmission reQuest (H-ARQ) and time diver...
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ISBN:
(纸本)9781467315449;9781467315425
Traditionally, a packet with errors, either due to channel noise or collisions, is discarded and needs to be retransmitted, leading to performance losses. Hybrid Automatic Retransmission reQuest (H-ARQ) and time diversity multipacket reception approaches, such as Network Diversity Multiple Access (NDMA), improve the system performance by requesting additional retransmissions and combining all the signals received together. However, the high round trip delay time associated to satellite networks introduces limitations in the number of retransmission requests that may be issued by the terminals to fulfill the Quality of Service (QoS) requirements. This paper considers the design of hybrid protocols combining H-ARQ and NDMA for satellite networks with demand-assigned traffic. The satellite NDMA (S-NDMA) protocol is presented and analytical models are proposed for its performance. Energy efficient QoS provisioning is also analyzed. The proposed system's performance is evaluated for a Low Earth Orbit (LEO) network with a Single-Carrier with Frequency Domain Equalization (SCFDE) scheme, and compared to H-NDMA. Results show that the proposed system is energy efficient and can provide enough QoS to support high demand services such as video telephony. (1)
作者：
Francisco GanhaoRui DinisLuis BernardoRodolfo OliveiraIT
Instituto de Telecomunicacoes Portugal CTS
Uninova Dep. de Eng Electrotecnica Faculdade de Ciencias e Tecnologia FCT Universidade Nova de Lisboa CTS
Uninova Dep. de Eng ElectrotecnicaFaculdade de Ciencias e Tecnologia FCT Universidade Nova de Lisboa
multipacket Reception (MPR) techniques employing either Direct Sequence Code Division Multiple Access (DS-CDMA) or Network Diversity Multiple Access (NDMA) have great potential to deal with packet collisions from mult...
详细信息
ISBN:
(纸本)9781467318808
multipacket Reception (MPR) techniques employing either Direct Sequence Code Division Multiple Access (DS-CDMA) or Network Diversity Multiple Access (NDMA) have great potential to deal with packet collisions from multiple Mobile Terminals (MTs). However, their performance evaluation in practical systems is difficult because lengthy simulations are needed to obtain the packet error rates for specific channel conditions. This paper considers MPR receivers based on the Iterative Block Decision Feedback Equalization (IB-DFE) concept. An analytical tool that computes the Bit Error Rate (BER) and Packet Error Rate (PER) for DS-CDMA is proposed, where its theoretical results have a good accuracy. This analytical approach, that provides a simple and relatively fast way to compute the BER and PER performance for DS-CDMA, is then employed for a comparison with NDMA. '
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