Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651691
A. Stelter
In the paper we propose a new random access scheme based on the tree algorithm for HIPERLAN/2 system. The proposed scheme defines both a random access method and a control scheme for allocation of random channels in the MAC frame. The simulation results show that the random channel throughput for the proposed scheme is higher than it can be achieved using slotted Aloha based HIPERLAN/2 solution
{"title":"Random access and channel allocation scheme for HIPERLAN/2 system","authors":"A. Stelter","doi":"10.1109/PIMRC.2005.1651691","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651691","url":null,"abstract":"In the paper we propose a new random access scheme based on the tree algorithm for HIPERLAN/2 system. The proposed scheme defines both a random access method and a control scheme for allocation of random channels in the MAC frame. The simulation results show that the random channel throughput for the proposed scheme is higher than it can be achieved using slotted Aloha based HIPERLAN/2 solution","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115219244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651902
N. S. Kambo, Syed Amjad Ali, E. A. Ince
This paper provides a simple approximation to pairwise error probability for memoryless fading channels when there is no channel state information at the decoder. The derived approximation is independent of the fading process and depends only on the mean and variance of the fading distribution. The new approximation is considerably better than an already existing approximation and a bound for low signal to noise ratio values. It can be applied to obtain average union upper bounds for block and turbo-like coding schemes. Plots for pairwise error probability for Rician, Rayleigh and Nakagami-m fading channels along with average union upper bounds for turbo codes with (1,5/7,5/7) generator polynomial are given to illustrate improvement in already published work
{"title":"A simple moment based approximation to pairwise error probability for memoryless fading channels","authors":"N. S. Kambo, Syed Amjad Ali, E. A. Ince","doi":"10.1109/PIMRC.2005.1651902","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651902","url":null,"abstract":"This paper provides a simple approximation to pairwise error probability for memoryless fading channels when there is no channel state information at the decoder. The derived approximation is independent of the fading process and depends only on the mean and variance of the fading distribution. The new approximation is considerably better than an already existing approximation and a bound for low signal to noise ratio values. It can be applied to obtain average union upper bounds for block and turbo-like coding schemes. Plots for pairwise error probability for Rician, Rayleigh and Nakagami-m fading channels along with average union upper bounds for turbo codes with (1,5/7,5/7) generator polynomial are given to illustrate improvement in already published work","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124990052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651403
D. Morgan
This paper explores the enhancement of WLAN downlink throughput in a conference room environment using a multi-antenna access point. The downlink transmission uses antenna patterns to spatially separate multiple users so that they can be served simultaneously, rather than sequentially, thereby speeding up the downlink throughput. This can be useful when several users are attempting to download long documents at the same time and sequential transmission causes a throughput bottleneck. A theoretical analysis with a room response model is used to obtain the statistics of separability in terms of minimum signal-to-interference-plus-noise ratio (SINR). It is shown that for this modeled conference room environment, a two-antenna access point can theoretically deliver a two-user minimum SINR of 18 dB for about 80% of the realizations, which would, neglecting overhead, likewise increase the throughput by 80%
{"title":"WLAN Downlink Throughput Enhancement in Conference Rooms Using a Multi-Antenna Access Point","authors":"D. Morgan","doi":"10.1109/PIMRC.2005.1651403","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651403","url":null,"abstract":"This paper explores the enhancement of WLAN downlink throughput in a conference room environment using a multi-antenna access point. The downlink transmission uses antenna patterns to spatially separate multiple users so that they can be served simultaneously, rather than sequentially, thereby speeding up the downlink throughput. This can be useful when several users are attempting to download long documents at the same time and sequential transmission causes a throughput bottleneck. A theoretical analysis with a room response model is used to obtain the statistics of separability in terms of minimum signal-to-interference-plus-noise ratio (SINR). It is shown that for this modeled conference room environment, a two-antenna access point can theoretically deliver a two-user minimum SINR of 18 dB for about 80% of the realizations, which would, neglecting overhead, likewise increase the throughput by 80%","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121399765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651901
I. Progri
A direct sequence spread spectrum (DSSS), orthogonal frequency division multiple access (OFDM), code division multiple access (CDMA) and frequency division multiple access (FDMA) (or MC-CDMA) indoor geolocation system is presented and discussed in this paper. The data sequence on the transmitter is spread in time using two spreading sequences and then is modulated employing a quadrature phase shift keying (QPSK) scheme. The channel is modeled as a slowly varying frequency-selective, Rayleigh fading channel typical of an indoor office building or factory. The receiver utilizes a non-coherent data demodulator to minimize the sensitivity of the receiver to the Rayleigh fading channel. The bit-error-probability (BEP) performance of this system is compared to that of a DSSS-CDMA-FDMA (or C-CDMA) system when operating in a Rayleigh fading channel with additive white Gaussian noise, range and Doppler shift. Performance results indicate superior performance of the coded MC-CDMA systems of roughly equal transmitter and post RF receiver complexity
{"title":"A MC-CDMA indoor geolocation system","authors":"I. Progri","doi":"10.1109/PIMRC.2005.1651901","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651901","url":null,"abstract":"A direct sequence spread spectrum (DSSS), orthogonal frequency division multiple access (OFDM), code division multiple access (CDMA) and frequency division multiple access (FDMA) (or MC-CDMA) indoor geolocation system is presented and discussed in this paper. The data sequence on the transmitter is spread in time using two spreading sequences and then is modulated employing a quadrature phase shift keying (QPSK) scheme. The channel is modeled as a slowly varying frequency-selective, Rayleigh fading channel typical of an indoor office building or factory. The receiver utilizes a non-coherent data demodulator to minimize the sensitivity of the receiver to the Rayleigh fading channel. The bit-error-probability (BEP) performance of this system is compared to that of a DSSS-CDMA-FDMA (or C-CDMA) system when operating in a Rayleigh fading channel with additive white Gaussian noise, range and Doppler shift. Performance results indicate superior performance of the coded MC-CDMA systems of roughly equal transmitter and post RF receiver complexity","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121602529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651940
G. Orfanos, B. Walke, Hans-Jürgen Reumerman, W. Butsch
Multi-carrier code division multiple access (MC-CDMA), a novel, high capacity, multicarrier modulation scheme, is developing to a key radio transmission technology for future wireless local area networks (W-LANs). However in ad hoc code division multiple access (CDMA) networks near-far effects can block a receiver due to high interference. These effects occur when a receiving station is closer to an interferer than to its corresponding transmitter. Accordingly, the receiver cannot detect the intended signal out of the received one and the data transmission fails. In this work, we present an adaptive medium access control (MAC) protocol for ad hoc MC-CDMA based W-LANs, based on the IEEE 802.11 MAC protocol. The new protocol has the ability to overcome the near-far-problem by employing a frequency adaptation method. The key of the proposed method is an interference estimate built at each receiving mobile station (MS). Aided by its estimate, a MS can calculate whether the quality of service (QoS) expectations of the incoming link can be accomplished. If the interference is too high, the receiving MS initiates a frequency channel change and informs the corresponding transmitter over the control packets about the Id of the new channel. It is shown that this concept can deploy the high capacity characteristics of MC-CDMA in wireless environments
{"title":"An adaptive MAC protocol for MC-CDMA ad hoc wireless LAN","authors":"G. Orfanos, B. Walke, Hans-Jürgen Reumerman, W. Butsch","doi":"10.1109/PIMRC.2005.1651940","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651940","url":null,"abstract":"Multi-carrier code division multiple access (MC-CDMA), a novel, high capacity, multicarrier modulation scheme, is developing to a key radio transmission technology for future wireless local area networks (W-LANs). However in ad hoc code division multiple access (CDMA) networks near-far effects can block a receiver due to high interference. These effects occur when a receiving station is closer to an interferer than to its corresponding transmitter. Accordingly, the receiver cannot detect the intended signal out of the received one and the data transmission fails. In this work, we present an adaptive medium access control (MAC) protocol for ad hoc MC-CDMA based W-LANs, based on the IEEE 802.11 MAC protocol. The new protocol has the ability to overcome the near-far-problem by employing a frequency adaptation method. The key of the proposed method is an interference estimate built at each receiving mobile station (MS). Aided by its estimate, a MS can calculate whether the quality of service (QoS) expectations of the incoming link can be accomplished. If the interference is too high, the receiving MS initiates a frequency channel change and informs the corresponding transmitter over the control packets about the Id of the new channel. It is shown that this concept can deploy the high capacity characteristics of MC-CDMA in wireless environments","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125223237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651665
G. Orfanos, B. Walke, J. W. Jansen, Hans-Jürgen Reumerman
Multi-carrier code division multiple access (MC-CDMA) is recently considered as a key technology for future wireless systems. Its high capacity and collision avoidance capability can fulfill the increasing demand for high throughput and quality of service (QoS). The application of MC-CDMA divides the frequency channel in many parallel channels, separated from each other in code domain. We refer to these parallel channels as code channels (cchs). In order to exploit the advantages of this spread spectrum technique, the medium access control (MAC) protocol has to be aware of the multichannel structure of the MC-CDMA network. Mobile stations (MSs) should be equally distributed among the cchs for better utilization of the resources and collision avoidance. Additionally, the assignment of a link to a cch should be done under consideration of the interference situation in the network. This is very important for the prompt operation of the link as the different cchs loose their orthogonality in asynchronous systems. In this paper we present an adaptive, interference aware MAC protocol for MC-CDMA adhoc wireless local area networks (WLANs), which adapts the allocation of resources to both interference and utilization degree of the different cchs, in order to achieve high capacity
{"title":"Interference aware adaptive MAC protocol for MC-CDMA ad hoc wireless LANs","authors":"G. Orfanos, B. Walke, J. W. Jansen, Hans-Jürgen Reumerman","doi":"10.1109/PIMRC.2005.1651665","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651665","url":null,"abstract":"Multi-carrier code division multiple access (MC-CDMA) is recently considered as a key technology for future wireless systems. Its high capacity and collision avoidance capability can fulfill the increasing demand for high throughput and quality of service (QoS). The application of MC-CDMA divides the frequency channel in many parallel channels, separated from each other in code domain. We refer to these parallel channels as code channels (cchs). In order to exploit the advantages of this spread spectrum technique, the medium access control (MAC) protocol has to be aware of the multichannel structure of the MC-CDMA network. Mobile stations (MSs) should be equally distributed among the cchs for better utilization of the resources and collision avoidance. Additionally, the assignment of a link to a cch should be done under consideration of the interference situation in the network. This is very important for the prompt operation of the link as the different cchs loose their orthogonality in asynchronous systems. In this paper we present an adaptive, interference aware MAC protocol for MC-CDMA adhoc wireless local area networks (WLANs), which adapts the allocation of resources to both interference and utilization degree of the different cchs, in order to achieve high capacity","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122395113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651835
Jong-Han Kim, K. Bae, A. Annamalai, Jeffrey H. Reed
Using analytical approach, we investigate the impact of spatial diversity on the Erlang capacity of reverse link direct sequence code division multiple access (DS/CDMA) system. Several parameters which can affect the capacity are considered: transmit diversity order, spatial receive diversity order, the number of multipaths, fade distribution and arbitrary multipath intensity profile, maximum transmit power, soft-handoff, and traffic distribution with call admission control scheme
{"title":"The impact of transmit diversity on the Erlang capacity of reverse link DS/CDMA system","authors":"Jong-Han Kim, K. Bae, A. Annamalai, Jeffrey H. Reed","doi":"10.1109/PIMRC.2005.1651835","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651835","url":null,"abstract":"Using analytical approach, we investigate the impact of spatial diversity on the Erlang capacity of reverse link direct sequence code division multiple access (DS/CDMA) system. Several parameters which can affect the capacity are considered: transmit diversity order, spatial receive diversity order, the number of multipaths, fade distribution and arbitrary multipath intensity profile, maximum transmit power, soft-handoff, and traffic distribution with call admission control scheme","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122823404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651908
Danke Xie, Jun Wang, O. Y. Wen, Shaoqian Li
Traditional irregular low-density parity-check (IR-LDPC) codes are constructed based on the irregular bipartite graphs with carefully chosen degree patterns on both sides and computer searching is usually applied, which leads complexity to be relatively high. In this paper, we introduce the concept of V-matrix which is a matrix composed of vectors and propose a new approach to construct the IR-LDPC codes. By introducing some special operations, we can obtain the desired sparse parity-check matrix for IR-LDPC codes design. Because computer searching is avoided, the complexity is efficiently reduced. Computer simulation results show that our approach can achieve good tradeoff between complexity and performance
{"title":"Construction of irregular low-density parity-check codes based on V-matrix","authors":"Danke Xie, Jun Wang, O. Y. Wen, Shaoqian Li","doi":"10.1109/PIMRC.2005.1651908","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651908","url":null,"abstract":"Traditional irregular low-density parity-check (IR-LDPC) codes are constructed based on the irregular bipartite graphs with carefully chosen degree patterns on both sides and computer searching is usually applied, which leads complexity to be relatively high. In this paper, we introduce the concept of V-matrix which is a matrix composed of vectors and propose a new approach to construct the IR-LDPC codes. By introducing some special operations, we can obtain the desired sparse parity-check matrix for IR-LDPC codes design. Because computer searching is avoided, the complexity is efficiently reduced. Computer simulation results show that our approach can achieve good tradeoff between complexity and performance","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127004185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651579
B. Ahlgren, L. Eggert, B. Ohlman, A. Schieder
Providing end-to-end communication in heterogeneous internetworking environments is a challenge. Two fundamental problems are bridging between different internetworking technologies and hiding of network complexity and differences from both applications and application developers. This paper presents abstraction and naming mechanisms that address these challenges in the Ambient Networks project. Connectivity abstractions hide the differences of heterogeneous internetworking technologies and enable applications to operate across them. A common naming framework enables end-to-end communication across otherwise independent internetworks and supports advanced networking capabilities, such as indirection or delegation, through dynamic bindings between named entities
{"title":"Ambient networks: bridging heterogeneous network domains","authors":"B. Ahlgren, L. Eggert, B. Ohlman, A. Schieder","doi":"10.1109/PIMRC.2005.1651579","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651579","url":null,"abstract":"Providing end-to-end communication in heterogeneous internetworking environments is a challenge. Two fundamental problems are bridging between different internetworking technologies and hiding of network complexity and differences from both applications and application developers. This paper presents abstraction and naming mechanisms that address these challenges in the Ambient Networks project. Connectivity abstractions hide the differences of heterogeneous internetworking technologies and enable applications to operate across them. A common naming framework enables end-to-end communication across otherwise independent internetworks and supports advanced networking capabilities, such as indirection or delegation, through dynamic bindings between named entities","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127610052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651899
A. Dudkov, V. Ipatov
Users' asynchronism and multipath propagation are among the most problematic issues in designing direct sequence code division multiple access (DS CDMA) systems. In this paper a system employing interleaved multiple signatures per user to mitigate the damaging effects of these factors is described and studied. It is demonstrated that interleaving along with an appropriate selection of users' signature multitudes drastically lowers the level of data-modulation-related peaks of multiple access interference
{"title":"Signature-interleaved DS CDMA: controlling odd correlation peaks","authors":"A. Dudkov, V. Ipatov","doi":"10.1109/PIMRC.2005.1651899","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651899","url":null,"abstract":"Users' asynchronism and multipath propagation are among the most problematic issues in designing direct sequence code division multiple access (DS CDMA) systems. In this paper a system employing interleaved multiple signatures per user to mitigate the damaging effects of these factors is described and studied. It is demonstrated that interleaving along with an appropriate selection of users' signature multitudes drastically lowers the level of data-modulation-related peaks of multiple access interference","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128106162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：