{"title":"Capacity of SIMO systems over non-identically independent Nakagami-m channels","authors":"Amer M. Magableh, M. Matalgah","doi":"10.1109/SARNOF.2007.4567395","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567395","url":null,"abstract":"The ergodic capacity of single input multiple output (SIMO) wireless communication systems over Nakagami-m fading channels is available in the literature for the case of identically independent distributed (i.i.d.) subchannels. However, the non- identically independent Nakagami-m case is more practical and has not been considered in the literature. In this paper, we derive an analytical expression for the ergodic capacity of SIMO wireless communication systems over non-identically independent Nakagami-m subchannels. We also derive an expression for the capacity of i.i.d. Nakagami-m case which requires much less computational time as compared to expressions reported in literature. Numerical results are presented and verified via Monte-Carlo simulation.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122935762","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}
{"title":"Robust asynchronous STBC transceiver for multiple-access frequency-selective channels","authors":"Dandan Wang, H. Minn, N. Al-Dhahir","doi":"10.1109/SARNOF.2007.4567357","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567357","url":null,"abstract":"In this paper, we propose a robust STBC transmission scheme to combat the timing synchronization errors over frequency-selective multiple-access channels. First, the equivalent channel model in the presence of timing synchronization errors is derived and we find that the synchronization errors result in an equivalent channel model with larger number of correlated channel taps. Based on this correlated equivalent channel model, the statistical power profile is analyzed and a robust statistical bit loading algorithm is proposed. At the receiver, by exploiting the algebraic structure of the Alamouti STBC, a closed-form expression of the QR receiver is derived which further simplifies computational complexity. Simulation results show that our proposed scheme is robust to timing synchronization errors.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125363985","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}
{"title":"Performance analysis of a 802.11a OFDM system in the presence of UWB and multipath interference","authors":"A. Mehbodniya, S. Aissa","doi":"10.1109/SARNOF.2007.4567388","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567388","url":null,"abstract":"In this paper we consider the coexistence issue between OFDM-based WLANs of the 802.11a family and time-hopping ultra wideband (TH-UWB) systems. A general analytical expression is provided for the bit error rate (BER) of the OFDM transceiver operating in the presence of UWB interference and the interferences caused by the multipath propagation phenomenon on the 802.11a OFDM signal, comprising intersymbol interference (ISI) and interchannel interference (ICI). Numerical results are provided to illustrate the severity of the performance degradation as a function of the intensity of the UWB interferers to the 802.11a receiver and their proximity to the latter. The effect of the UWB system parameters to reduce its inflicted interference is also addressed. Such design can allow for an acceptable level of interference for these systems to coexist.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"79 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115658674","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}
{"title":"Probabilistic short-term delay and throughput requirements of multimedia services in high throughput wireless networks","authors":"T. Kastrinogiannis, S. Papavassiliou","doi":"10.1109/SARNOF.2007.4567361","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567361","url":null,"abstract":"In this paper userspsila short-term delay and throughput fundamental properties under basic opportunistic scheduling policies, required to support high throughput wireless communication systems with integrated multimedia services, are studied. Among the objectives of this work is to determine at what extent opportunistic scheduling policies can be used to support real-time services in addition to non-real time services. To achieve this, an appropriate framework for computing the corresponding properties under opportunistic scheduling policies is provided. Based on it, analytical expressions and numerical results regarding userspsila both throughput and access-time properties under basic opportunistic schedulers are provided, and the main system regulating parameters that affect the userspsila performance are identified and discussed.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114930611","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}
{"title":"Coherent versus differential mobile OFDM with application to DVB-H","authors":"Sili Lu, N. Al-Dhahir","doi":"10.1109/SARNOF.2007.4567324","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567324","url":null,"abstract":"Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H), which is required to operate under high mobility conditions resulting in significant Inter-carrier Interference (ICI). To mitigate ICI, several cancellation schemes have been proposed but they require reliable channel information at the receiver which is quite challenging and costly under high mobility. To overcome these challenges, we investigate non-coherent detection as an alternative for the DVB-H system, and combine it with different ICI mitigating techniques that do not require channel information. Our simulation results show that the proposed non-coherent environment schemes outperform the coherent schemes in typical DVB-H scenarios.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127163844","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}
{"title":"Radio resource management for OFDMA uplinks","authors":"Patrick Hosein","doi":"10.1109/SARNOF.2007.4567344","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567344","url":null,"abstract":"The next generation of wireless networks (4G) will use OFDMA (Orthogonal Frequency Division Multiple Access) in the reverse link. In OFDMA, the reverse link resources assigned to a user are called tiles each of which consists of a subset of consecutive subcarriers. Since at most one user is assigned to each of these tiles then reverse link transmissions within a sector are orthogonal. However, the transmission is affected by intercell interference since users in adjacent sectors may also have been assigned to the same tile. If those users in the adjacent sectors transmitted with high power then the intercell interference may severely limit the SINR achieved by the user. Therefore user transmission powers must be carefully managed to avoid excessive intercell interference. In this paper we propose a distributed algorithm for the problem and use numerical results to illustrate its performance.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126400724","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}
M. Haidar, R. Akl, H. Al‐Rizzo, Yupo Chan, R. Adada
{"title":"Optimal load distribution in large scale WLAN networks utilizing a power management algorithm","authors":"M. Haidar, R. Akl, H. Al‐Rizzo, Yupo Chan, R. Adada","doi":"10.1109/SARNOF.2007.4567386","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567386","url":null,"abstract":"In this paper we present an algorithm, based on power management of access points (AP), to reduce congestion in wireless local area networks (WLANs). The algorithm finds the most congested access point (MCAP) and adjusts its transmitted power in discrete steps and determines the optimal userspsila assignment such that an optimal load distribution is achieved. Results show that the algorithm is capable of significantly reducing the overall congestion in the WLAN.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128333544","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}
Jiann-Liang Chen, Ming-Chiao Chen, Tsui-Lien Chiang, Yao-Chung Chang, F. Shih
{"title":"Distributed fermat-point location estimation for wireless sensor network applications","authors":"Jiann-Liang Chen, Ming-Chiao Chen, Tsui-Lien Chiang, Yao-Chung Chang, F. Shih","doi":"10.1109/SARNOF.2007.4567317","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567317","url":null,"abstract":"This paper presents a distributed fermat-point range estimation strategy, which is important in the moving sensor localization applications. The fermat-point is defined as a point which minimizes the sum of distances from three sensors inside a triangle. This point is indeed at the trianglepsilas center of gravity. We solve the problems of large errors and poor performance in the bounding box algorithm. We obtain two results by performance analysis for a deployed environment with 200 sensor nodes. First, when the number of sensor nodes is below 150, the mean error decreases rapidly as the node density increases, and when the number of sensor nodes exceeds 170, the mean error stays below 1%. Second, when the number of beacon nodes is below 60, the normal nodes do not have sufficient number of accurate beacon nodes to help them estimate their locations. However, when the number of beacon nodes exceeds 60, the mean error changes slightly. Simulation results indicated that the proposed algorithm for sensor position estimation is more accurate than existing algorithms and improves on existing bounding box strategies.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"374 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116568086","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}
{"title":"New directions in covert malware modeling which exploit white-listing","authors":"Jisheng Wang, G. Kesidis, David J. Miller","doi":"10.1109/SARNOF.2007.4567340","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567340","url":null,"abstract":"Zero-day attacks - especially those that hide the attack exploit by using code obfuscation and encryption - remain a formidable challenge to existing network defenses. Many techniques have been developed that can address known attacks and similar new attacks that may arise in the future. Some methods, like Earlybird and Polygraph, focus on string-based content prevalence in payloads; others focus on the presence of particular I386 instructions, e.g., Sigfree counts the number of ldquousefulrdquo instructions in each request. For both types of systems, a white-listing mechanism, in which some strings or instructions are regarded as innocuous, is necessary to avoid a high false positive rate associated with common content such as URL addresses and peer-to-peer traffic. In this paper, we explore a more sophisticated attack model that not only makes malcode payloads look like nominal ones, but which is also assumed to be both aware of and exploitative of the white-listing itself in forming a Trojan mechanism. In other words, the malware attempts to embed its malcode into the prevalent content that is normally white-listed. If the malcode is encrypted, the attacker will also attempt to obfuscate its plain-text decryption code as much as possible. Both current string-based and instructionbased systems will likely fail to detect such attacks. We propose a comprehensive IDS model in the paper and discuss some potential defensive mechanisms against such attack.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"93 13","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113940579","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}
{"title":"Investigations of cross-layer designs for mobile ad hoc networks","authors":"Xiaoyu Hu, Yu-dong Yao, C. Graff, T. Cook","doi":"10.1109/SARNOF.2007.4567330","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567330","url":null,"abstract":"This paper explores the attributes, layering models and objective functions in cross layer designs for mobile ad hoc wireless networks by taking all the statistical characteristics and constraints from the physical (PHY) layer, media access control (MAC) layer and network (NET) layer into consideration. This paper reviews the entire network optimization across all the PHY/MAC/NET layers. At the PHY layer, the adaptive modulation, adaptive channel allocation and adaptive power control are employed according to the channel conditions and different quality of service (QoS) requirements of different services. The PHY layer constraint is specified in terms of target signal to noise and interference ratio (SINR) or target bit-error-ratio (BER). At the MAC layer, a feasible scheduling policy that maximizes the overall system performance for given fairness/QoS requirements is explored through the utility functions that build a bridge between the PHY layer and MAC layer to balance the efficiency and fairness. At the NET layer, the QoS requirements include call blocking probabilities, call connection delays, packet congestion probabilities and packet loss rates. By interacting with PHY layer and MAC layer constraints, a long-term network performance is investigated at the NET layer subject to both call-level and packet-level QoS requirements.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"504 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132479553","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}