Pub Date : 2005-09-11DOI: 10.1109/PIMRC.2005.1651603
A. B. Sediq, M. El-Tarhuni
In this paper, a new technique for power allocation to transmitted bits according to their significance on the message quality is presented. The proposed scheme is based on optimizing the power allocation to minimize the mean-square error rather than the bit error probability of image and video signals transmitted over fading wireless channels. An analytical framework for the power allocation technique is developed. Two techniques of power allocation; fixed and adaptive, are investigated in the paper. Simulation results show that the proposed scheme provides a gain of about 3 dB in Eb/N0 in AWGN channels and about 4 dB in flat fading channels over conventional equal-power allocation system. This gain is achieved without any increase in bandwidth, as opposed to that achieved with channel coding. The gains achieved with this algorithm come at the expense of slight increase in the peak-to-average power ratio of the transmitted signal
{"title":"MMSE power allocation for image and video transmission over wireless channels","authors":"A. B. Sediq, M. El-Tarhuni","doi":"10.1109/PIMRC.2005.1651603","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651603","url":null,"abstract":"In this paper, a new technique for power allocation to transmitted bits according to their significance on the message quality is presented. The proposed scheme is based on optimizing the power allocation to minimize the mean-square error rather than the bit error probability of image and video signals transmitted over fading wireless channels. An analytical framework for the power allocation technique is developed. Two techniques of power allocation; fixed and adaptive, are investigated in the paper. Simulation results show that the proposed scheme provides a gain of about 3 dB in Eb/N0 in AWGN channels and about 4 dB in flat fading channels over conventional equal-power allocation system. This gain is achieved without any increase in bandwidth, as opposed to that achieved with channel coding. The gains achieved with this algorithm come at the expense of slight increase in the peak-to-average power ratio of the transmitted signal","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":"125574880","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.2005.1651435
Hua Zhang, Geoffrey Y. Li
To obtain the closed-loop capacity of a multiple-input and multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system, channel state information (CSI) is required at the transmitter. Sometimes, CSI can be only obtained through frequent feedback from the receiver and it occupies a large bandwidth in the reverse link to completely feedback CSI. To reduce the data rate of CSI feedback, precoding matrix has been proposed for MIMO systems in flat fading channels and it is also extended to MIMO-OFDM systems in frequency-selective fading channels by interpolation. In this paper, we develop a novel precoding matrix tracking approach for MIMO-OFDM systems. The proposed approach is based on subspace tracking in the Grassman manifold and requires a limited data rate feedback. It not only is flexible to multiple data transmission but also has better performance than the existing approaches
{"title":"A Tracking Approach for Precoded MIMO-OFDM Systems with Low Data Rate CSI Feedback","authors":"Hua Zhang, Geoffrey Y. Li","doi":"10.1109/PIMRC.2005.1651435","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651435","url":null,"abstract":"To obtain the closed-loop capacity of a multiple-input and multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system, channel state information (CSI) is required at the transmitter. Sometimes, CSI can be only obtained through frequent feedback from the receiver and it occupies a large bandwidth in the reverse link to completely feedback CSI. To reduce the data rate of CSI feedback, precoding matrix has been proposed for MIMO systems in flat fading channels and it is also extended to MIMO-OFDM systems in frequency-selective fading channels by interpolation. In this paper, we develop a novel precoding matrix tracking approach for MIMO-OFDM systems. The proposed approach is based on subspace tracking in the Grassman manifold and requires a limited data rate feedback. It not only is flexible to multiple data transmission but also has better performance than the existing approaches","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"47 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":"126954285","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.2005.1651624
H. Puska, H. Saarnisaari, J. Iinatti
This paper introduces a method used for code synchronization in direct sequence spread spectrum (DS/SS) systems when the receiver is equipped with a smart antenna followed by the matched filter (MF). The presented method first estimates the direction-of-arrival (DOA) of the DS-signal, then performs beamforming, and finally makes synchronization decision based on the maximum output of the MF. Because the amount of data needed in DOA estimation depends on the prevailing signal-to-noise ratio (SNR), the proposed method operates iteratively. The method starts by collecting a piece of data for DOA estimation. Due to the inaccurate DOA estimation, the main beam of the radiation pattern may be steered to erroneous direction and code acquisition may be failed. After a fail more data is collected and the accuracy of DOA estimate improves. This process is repeated until DOA and delay estimation succeeds. The results show that it is advantageous to start by collecting only a small amount of data for DOA estimation because the shortest mean acquisition times are achieved in that case
{"title":"An iterative method for code acquisition using DOA estimation and beamforming","authors":"H. Puska, H. Saarnisaari, J. Iinatti","doi":"10.1109/PIMRC.2005.1651624","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651624","url":null,"abstract":"This paper introduces a method used for code synchronization in direct sequence spread spectrum (DS/SS) systems when the receiver is equipped with a smart antenna followed by the matched filter (MF). The presented method first estimates the direction-of-arrival (DOA) of the DS-signal, then performs beamforming, and finally makes synchronization decision based on the maximum output of the MF. Because the amount of data needed in DOA estimation depends on the prevailing signal-to-noise ratio (SNR), the proposed method operates iteratively. The method starts by collecting a piece of data for DOA estimation. Due to the inaccurate DOA estimation, the main beam of the radiation pattern may be steered to erroneous direction and code acquisition may be failed. After a fail more data is collected and the accuracy of DOA estimate improves. This process is repeated until DOA and delay estimation succeeds. The results show that it is advantageous to start by collecting only a small amount of data for DOA estimation because the shortest mean acquisition times are achieved in that case","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"261 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":"115596276","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.2005.1651786
T. Weber, M. Meurer
The demand for accurate positioning of mobile terminals for emergency services like E911 inspired extensive research not only on position estimation in mobile radio scenarios but also on new location based services. Unfortunately, mobile radio scenarios are characterized by shadowing and multipath propagation, which renders accurate position estimation a difficult task. This is especially true for indoor scenarios. Both position estimation based on satellite signals like GPS or GALILEO and position estimation based on the mobile radio system's signals suffer from these adverse propagation conditions. In the present paper we just accept that initial position estimates in mobile radio scenarios are rather rough. We focus on combining multiple successively obtained rough position estimates in order to obtain improved estimates of the path on which the mobile terminal moved or of the position at a certain time instant. When combining position estimates we have to consider that the mobile terminal may move during the measurement period in which the initial position estimates are obtained. We describe the mobility of the mobile terminal by a Markoff Model, whose states correspond to the positions, and apply the theory of hidden Markoff models for obtaining the improved position estimates
{"title":"Temporal post-processing of position estimates exploiting Markoff models","authors":"T. Weber, M. Meurer","doi":"10.1109/PIMRC.2005.1651786","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651786","url":null,"abstract":"The demand for accurate positioning of mobile terminals for emergency services like E911 inspired extensive research not only on position estimation in mobile radio scenarios but also on new location based services. Unfortunately, mobile radio scenarios are characterized by shadowing and multipath propagation, which renders accurate position estimation a difficult task. This is especially true for indoor scenarios. Both position estimation based on satellite signals like GPS or GALILEO and position estimation based on the mobile radio system's signals suffer from these adverse propagation conditions. In the present paper we just accept that initial position estimates in mobile radio scenarios are rather rough. We focus on combining multiple successively obtained rough position estimates in order to obtain improved estimates of the path on which the mobile terminal moved or of the position at a certain time instant. When combining position estimates we have to consider that the mobile terminal may move during the measurement period in which the initial position estimates are obtained. We describe the mobility of the mobile terminal by a Markoff Model, whose states correspond to the positions, and apply the theory of hidden Markoff models for obtaining the improved position estimates","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"40 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":"122625834","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.2005.1651511
C. Ribeiro, A. Richter, V. Koivunen
In this paper we derive an estimator for both time-delay and angular channel propagation parameters of the diffuse scattering component that is frequently observed in channel sounding measurements. The joint angular-delay model leads to correlation matrix with high dimensionality, which prevents direct implementation of a maximum-likelihood (ML) estimator using finite precision arithmetics and finite memory resources. We derive low complexity methods for computing the ML estimates that exploit the structure of the covariance matrices. The estimator is based on a two step procedure: first, the parameters of the power delay profile are estimated, as well as measurement noise power. Then, using the estimated time-delay parameters, the parameters of the angular distributions are estimated. We present simulation results and compare the estimated time-delay and angular distributions to the actual distributions, showing that high precision estimates are obtained
{"title":"Stochastic Maximum Likelihood Estimation of Angle- and Delay-Domain Propagation Parameters","authors":"C. Ribeiro, A. Richter, V. Koivunen","doi":"10.1109/PIMRC.2005.1651511","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651511","url":null,"abstract":"In this paper we derive an estimator for both time-delay and angular channel propagation parameters of the diffuse scattering component that is frequently observed in channel sounding measurements. The joint angular-delay model leads to correlation matrix with high dimensionality, which prevents direct implementation of a maximum-likelihood (ML) estimator using finite precision arithmetics and finite memory resources. We derive low complexity methods for computing the ML estimates that exploit the structure of the covariance matrices. The estimator is based on a two step procedure: first, the parameters of the power delay profile are estimated, as well as measurement noise power. Then, using the estimated time-delay parameters, the parameters of the angular distributions are estimated. We present simulation results and compare the estimated time-delay and angular distributions to the actual distributions, showing that high precision estimates are obtained","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"27 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":"114191337","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.2005.1651896
Bingyang Wu, Shixin Cheng, Haifeng Wang
OFDM symbols exhibit a property of high peak-to-average power ratios (PAPR), which degrades system performance. Partial transmit sequence (PTS) is a kind of methods to depress the PAPR effectively. To obtain good trade-offs between complexity and performance on PAPR reduction using PTS schemes, a trellis structure based PTS factor search method is proposed and investigated in this paper. The trellis search is with a variant constraint length LC, 1lesLClesV-1, where V is the number of PTS sub-blocks. The method is to decide a PTS factor by searching all possible paths obtained by varying LC consecutive factors. Using different constraint length, trellis factor search PTS exhibits different PAPR reduction performance with different computation burden. The trellis search can be viewed as a general PTS factor search model including the full search and the iterative search appeared in previous papers
{"title":"Trellis factor search PTS for PAPR reduction in OFDM","authors":"Bingyang Wu, Shixin Cheng, Haifeng Wang","doi":"10.1109/PIMRC.2005.1651896","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651896","url":null,"abstract":"OFDM symbols exhibit a property of high peak-to-average power ratios (PAPR), which degrades system performance. Partial transmit sequence (PTS) is a kind of methods to depress the PAPR effectively. To obtain good trade-offs between complexity and performance on PAPR reduction using PTS schemes, a trellis structure based PTS factor search method is proposed and investigated in this paper. The trellis search is with a variant constraint length LC, 1lesLClesV-1, where V is the number of PTS sub-blocks. The method is to decide a PTS factor by searching all possible paths obtained by varying LC consecutive factors. Using different constraint length, trellis factor search PTS exhibits different PAPR reduction performance with different computation burden. The trellis search can be viewed as a general PTS factor search model including the full search and the iterative search appeared in previous papers","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"35 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":"114553539","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.2005.1651914
Xuecheng Qian
In contrast to traditional receiver where sampling happens at baseband, the bandpass-sampling receiver offers more flexibility since more signal processing is implemented in the digital domain. For this type of receivers, the sampling frequency is a very important factor since it influences both receiver performance and implementation efficiency. In this paper, the allowable sampling frequencies are analyzed for the bandpass-sampling receiver in practical cases with out-of-band interference. Preferable choices of sampling frequency are then provided
{"title":"Choice of sampling frequency for bandpass-sampling receiver","authors":"Xuecheng Qian","doi":"10.1109/PIMRC.2005.1651914","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651914","url":null,"abstract":"In contrast to traditional receiver where sampling happens at baseband, the bandpass-sampling receiver offers more flexibility since more signal processing is implemented in the digital domain. For this type of receivers, the sampling frequency is a very important factor since it influences both receiver performance and implementation efficiency. In this paper, the allowable sampling frequencies are analyzed for the bandpass-sampling receiver in practical cases with out-of-band interference. Preferable choices of sampling frequency are then provided","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"35 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":"122114279","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.2005.1651818
Mohammed Atiquzzaman, A. Reaz
Mobility of Internet hosts allows computing nodes to move between subnets. Mobility can be handled at different layers of the protocol stack, with network and transport layer mobility being the most widely studied. Transport layer mobility can overcome many of the limitations of network layer schemes like mobile IP. Various approaches have been proposed to implement mobility in the transport layer. In this paper, we discuss a number of transport layer mobility schemes, classify them according to their approach, and compare them based on a number of evaluation criteria
{"title":"Survey and classification of transport layer mobility management schemes","authors":"Mohammed Atiquzzaman, A. Reaz","doi":"10.1109/PIMRC.2005.1651818","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651818","url":null,"abstract":"Mobility of Internet hosts allows computing nodes to move between subnets. Mobility can be handled at different layers of the protocol stack, with network and transport layer mobility being the most widely studied. Transport layer mobility can overcome many of the limitations of network layer schemes like mobile IP. Various approaches have been proposed to implement mobility in the transport layer. In this paper, we discuss a number of transport layer mobility schemes, classify them according to their approach, and compare them based on a number of evaluation criteria","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"8 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":"122128065","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.2005.1651517
D. Laselva, Xiongwen Zhao, J. Meinilä, T. Jämsä, J. Nuutinen, P. Kyösti, L. Hentilä
The modeling results from wideband radio channel measurements are presented for two environments: rural and indoor. The paper focuses on the average and instantaneous characteristics of received power including: path loss, shadow fading, power delay profiles, and rms delay spreads. Furthermore, the cross correlation between shadowing of the path loss and the delay spread is investigated and found to be large. Doppler measurement campaigns were conducted in both environments, at 2.45 GHz and 5.25 GHz along the same measurement routes, with 100 MHz bandwidth. In this paper it is shown that we may apply 2.45 GHz band small scale models into 5.25 GHz band. It can be also seen, as for the measured scenarios, on average, the difference in terms of path loss between 2.45 GHz and 5.25 GHz in line-of-sight indoor environment, where waveguide effect is encountered, is c.a. 8 dB, instead in rural outdoor the mentioned difference is c.a. 6 dB
给出了两种环境下宽带无线信道测量的建模结果:农村和室内。本文重点研究了接收功率的平均和瞬时特性，包括路径损耗、阴影衰落、功率延迟分布和均方根延迟扩展。此外，研究了路径损失的阴影与延迟扩展之间的相互关系，发现路径损失的阴影与延迟扩展之间的相互关系很大。多普勒测量活动在两种环境下进行，在2.45 GHz和5.25 GHz沿着相同的测量路线，100 MHz带宽。本文表明，我们可以将2.45 GHz频段的小比例模型应用到5.25 GHz频段。还可以看到，在测量的场景中，在遇到波导效应的视距室内环境中，2.45 GHz和5.25 GHz之间的路径损耗平均差异约为8 dB，而在农村室外，上述差异约为6 dB
{"title":"Empirical Models and Parameters for Rural and Indoor Wideband Radio Channels At 2.45 and 5.25 GHZ","authors":"D. Laselva, Xiongwen Zhao, J. Meinilä, T. Jämsä, J. Nuutinen, P. Kyösti, L. Hentilä","doi":"10.1109/PIMRC.2005.1651517","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651517","url":null,"abstract":"The modeling results from wideband radio channel measurements are presented for two environments: rural and indoor. The paper focuses on the average and instantaneous characteristics of received power including: path loss, shadow fading, power delay profiles, and rms delay spreads. Furthermore, the cross correlation between shadowing of the path loss and the delay spread is investigated and found to be large. Doppler measurement campaigns were conducted in both environments, at 2.45 GHz and 5.25 GHz along the same measurement routes, with 100 MHz bandwidth. In this paper it is shown that we may apply 2.45 GHz band small scale models into 5.25 GHz band. It can be also seen, as for the measured scenarios, on average, the difference in terms of path loss between 2.45 GHz and 5.25 GHz in line-of-sight indoor environment, where waveguide effect is encountered, is c.a. 8 dB, instead in rural outdoor the mentioned difference is c.a. 6 dB","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"44 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":"116998268","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.2005.1651660
Feng Xu, M. Grünewald, U. Rückert
In the context of single frequency band and omnidirectional communication, the throughput of wireless network is interference limited. Collision may occur if other signals impinge the destination while it is receiving the intended signal. To prevent collisions, CSMA/CA is applied to serialize the communication tasks. Recently, numerous directional schemes have been proposed to further increase the network throughput. In this paper, a practical scheme for directional communication based on a simplified switched beam technique is proposed on the physical layer. Additionally, the corresponding modifications on the CSMA/CA protocol are also studied to optimize the overall system performance. It is worthy of notice that this scheme is feasible for the mobile portable device under state-of-the-art technologies in terms of dimension, power consumption, hardware complexity and computing requirements. Preliminary simulations show that this scheme can increase the network throughput up to two times compared to an omni-directional system at the cost of only 10% higher power consumption
{"title":"A low complexity directional scheme for mobile ad hoc networks","authors":"Feng Xu, M. Grünewald, U. Rückert","doi":"10.1109/PIMRC.2005.1651660","DOIUrl":"https://doi.org/10.1109/PIMRC.2005.1651660","url":null,"abstract":"In the context of single frequency band and omnidirectional communication, the throughput of wireless network is interference limited. Collision may occur if other signals impinge the destination while it is receiving the intended signal. To prevent collisions, CSMA/CA is applied to serialize the communication tasks. Recently, numerous directional schemes have been proposed to further increase the network throughput. In this paper, a practical scheme for directional communication based on a simplified switched beam technique is proposed on the physical layer. Additionally, the corresponding modifications on the CSMA/CA protocol are also studied to optimize the overall system performance. It is worthy of notice that this scheme is feasible for the mobile portable device under state-of-the-art technologies in terms of dimension, power consumption, hardware complexity and computing requirements. Preliminary simulations show that this scheme can increase the network throughput up to two times compared to an omni-directional system at the cost of only 10% higher power consumption","PeriodicalId":248766,"journal":{"name":"2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications","volume":"2 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":"129769311","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：