{"title":"On multiuser MIMO capacity benefits in air-to-ground communication for air traffic management","authors":"Jawad Rasool, G. Øien, J. Håkegård, T. A. Myrvoll","doi":"10.1109/ISWCS.2009.5285292","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285292","url":null,"abstract":"In this paper, we focus on communication from airplanes to Air traffic Control (ATC) towers at airports, employing multiple antennas at the ATC. The whole air-to-ground communication system can then be modeled as a MIMO MAC channel with mobile users. The main aim is to demonstrate that multiuser MIMO systems can be useful for achieving spectrally efficient aeronautical communications, to quantify the achievable capacity gains when using such systems, and to show that they can be implemented by deploying multiple antennas at reasonable inter-antenna distances at the ATC. In particular, we analyze the issue of antenna separation of a uniform linear array (ULA) at the ATC, for the case of line of sight (LoS) air-to-ground channels. It turns out that at high frequency (1 GHz), the use of large ULAs is indeed possible since the maximum (ergodic) capacity gain is achieved already for antenna separation on the order of a few centimeters. We also observe the system performance in Ricean fading channels. The performance is evaluated with respect to ergodic multiuser capacity throughout.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122226716","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":"Optimum joint detection using soft decision combined with maximum gradient search","authors":"Khalid Al Murrani","doi":"10.1109/ISWCS.2009.5285221","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285221","url":null,"abstract":"The number of computations required by the optimum maximum likelihood receiver to make a decision on the received signal vector grows exponentially with the number of users in a multiuser CDMA environment which makes it too complex to implement practically. In this paper we suggest a modification in the approach of this receiver to arrive at the maximum likelihood decision. Instead of comparing the received vector for all possible combinations of the transmitted data vector, we use the gradient method to scale the surface of the decision metric in the direction of the optimum maximizing point. Combining this with soft decision by restricting the movement by one dimension at a time after making a decision along the respective axis, we can arrive at the maximum likelihood decision with a number of computations that increases quadratically rather than exponentially with the number of users. Results show that the performance of the optimum receiver using this approach is virtually indistinguishable from the standard computationally intensive approach.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114969784","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":"Achievable rates in the SIMO-Uplink/MISO-downlink of an FDD system with imperfect CSI","authors":"M. Castañeda, Anup Chathoth, J. Nossek","doi":"10.1109/ISWCS.2009.5285255","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285255","url":null,"abstract":"In practical systems, the available CSI for coherent transmission can not always be assumed to be perfect. For instance, in the MISO-downlink of a single-user FDD system with multiple antennas at the BS and a single antenna at the user, the available transmit CSI is actually estimated, quantized, outdated and affected by feedback errors. On the other hand, in the reverse link of this FDD system, i.e. the SIMO-uplink, the available receive CSI is only estimated. The two links of this FDD system represent a two-way system, in which we encounter a tradeoff between the MISO-downlink and SIMO-uplink rate due to the feedback of the transmit CSI in the uplink. Taking into account this tradeoff, we analyze the achievable rates in both links of the described FDD system considering imperfect CSI and limited feedback.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115261707","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":"Analog distributed source-channel coding using sinusoids","authors":"J. Karlsson, M. Skoglund","doi":"10.1109/ISWCS.2009.5285266","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285266","url":null,"abstract":"In a wireless sensor network, it is likely that the measurements of the sensors are correlated. Distributed source coding can be used to reduce transmission rate or mitigate the effects of the channel noise in the case of analog transmission. In this paper, we propose a novel scheme for implementing distributed source-channel coding based on analog mappings. We assume that an analog source is to be transmitted to a receiver that has access to correlated side information, as in the Wyner-Ziv problem. From the Cramér-Rao lower bound, we observe general properties of analog distributed source-channel mappings. It is especially clear how the stretch factor influences the performance. From this observation we propose two different mappings based on sinusoidal waveforms. The proposed transmission scheme is numerically evaluated and shown to perform well, particularly in the low-SNR regime. Furthermore, it requires no encoding or decoding delay, making it suitable for delay-critical applications in wireless sensor networks.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114077094","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":"Effects of relay position and power allocation in space-time coded cooperative wireless systems","authors":"L. Zuari, A. Conti, V. Tralli","doi":"10.1109/ISWCS.2009.5285258","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285258","url":null,"abstract":"Cooperative communications are effective in improving the performance and extend the coverage of wireless networks. One issue is to find proper methods to allocate cooperative nodes. In this paper we investigate the effects of relay position and power allocation strategy in cooperative communications employing space-time codes (STCs). We consider non-ideal links between source, relay, and destination enabling the analysis of relay allocation problem based on the performance of each link in realistic scenarios. The frame error rate for various channel conditions, available diversity, relays position, and transmitted power levels is obtained. Both the situation of balanced and unbalanced transmit power levels for source, relay, and destination are compared. Cooperative pragmatic STC in block fading channel (BFC) are considered for our analysis. The results provide insights on how to allocate relay nodes based on geometry, link quality, and transmitted power considerations.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122724644","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":"Optimizing system capacity and application delays in WiMAX networks","authors":"Iwan Adhicandra, R. Garroppo, S. Giordano","doi":"10.1109/ISWCS.2009.5285247","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285247","url":null,"abstract":"The IEEE 802.16 technology (WiMAX) is a promising technology for providing last-mile connectivity by radio link due to its large coverage area, low cost of deployment and high speed data rates. However, the maximum number of channels defined in the current system may cause a potential bottleneck and limit the overall system capacity. The aim of this paper is to compare the impact on system performance of different solutions used to mitigate the impairments due to the radio channel. In particular, taking into account the WiMAX system capacity as well as application delays, the paper presents the simulation results obtained when a static QPSK ½ Modulation and Coding Scheme (MCS) is adopted. Then, the study is aimed at evaluating the improvements introduced by the adoption of an adaptive modulation and coding (AMC) and an AMC jointly with Hybrid Automatic Repeat reQuest (HARQ). Results indicate that the best strategy is to use an aggressive AMC table with HARQ.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128479698","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}
D. Çavdar, Huseyin Birkan Yilmaz, T. Tuğcu, F. Alagoz
{"title":"Resource planning in cognitive radio networks","authors":"D. Çavdar, Huseyin Birkan Yilmaz, T. Tuğcu, F. Alagoz","doi":"10.1109/ISWCS.2009.5285240","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285240","url":null,"abstract":"Cognitive radio is a new paradigm in the evolution of wireless communications to improve spectrum efficiency significantly by utilizing white spaces. In this paper, the mathematical model of the cognitive radio simulator that we develop is introduced and resource planning algorithms for cognitive radio networks is considered. A new resource planning method, which is a fixed assignment strategy, is introduced. The proposed method improves probability of blocking, dropping, and forced termination compared to uniform assignment. Proposed method includes offered traffic, hop count to the most loaded cell, and velocity of mobile users as parameter. Performance of the proposed method is evaluated with the cognitive radio network simulator that is developed.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121773421","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":"Perceptual-based quality assessment of error protection schemes for wireless JPEG2000","authors":"M. Iqbal, H. Zepernick, U. Engelke","doi":"10.1109/ISWCS.2009.5285217","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285217","url":null,"abstract":"Designing wireless imaging services with acceptable quality imposes great challenges due to the severe impairments induced by wireless channels, high data rate demands and limited transmission bandwidth. In this paper, we examine different error protection schemes for the JPEG2000 codestream using the error control codes offered by the wireless JPEG2000 (JPWL) standard. In particular, two unequal error protection (UEP) schemes are considered. In the first scheme, only the initial and more important packets of the JPWL codestream are protected while the remaining packets are left without protection. In contrast, the second scheme uses a strong code for the initial packets while a weaker code is used for the tail packets. As quality of visual services may not be captured adequately with traditional link layer metrics, code selection and their performance assessment is based on perceptual quality metrics. Specifically, the LP-norm, structural similarity (SSIM) index and visual information fidelity (VIF) criterion are utilized. Numerical results are provided for a range of system conditions under which UEP outperforms conventional equal error protection in terms of perceptual quality metrics.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121803889","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}
R. Garroppo, S. Giordano, D. Iacono, A. Cignoni, M. Falzarano
{"title":"On the WiMAX robustness against interfering signals in emergency marine scenario","authors":"R. Garroppo, S. Giordano, D. Iacono, A. Cignoni, M. Falzarano","doi":"10.1109/ISWCS.2009.5285268","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285268","url":null,"abstract":"This paper presents some experimental results about the robustness of a WiMAX system against interfering signals. In particular, this work presents a WiMAX performance comparison when two different types of interfering signals were generated: a continuous wave and a rectangular pulsed wave. Both of them were tuned at the same working frequency of the WiMAX system (i.e. 2.55 GHz). The former is typical of some attackers or dud devices, the latter, instead, is very similar to the signals generated by radars. In this work IP throughput performance and the VoIP (Voice over IP) perceived Quality of Service (QoS) were evaluated, when one of the two considered signals interfered the Base Station (BS) or the Costumer Premise Equipment (CPE). The experimental results point out that the continuous wave was more critical than the pulsed one for the WiMAX system; in some situation it caused the complete disconnection of the CPE from the BS or the BS outage.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"134 20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117259767","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":"Non-binary split LDPC codes defined over finite groups","authors":"B. Shams, D. Declercq, V. Heinrich","doi":"10.1109/ISWCS.2009.5285264","DOIUrl":"https://doi.org/10.1109/ISWCS.2009.5285264","url":null,"abstract":"In this paper, we propose a practically implementable decoding algorithm for split LDPC codes with parity constraints defined over finite groups. The proposed decoding algorithm generalizes the orders of the variable and check nodes such that it may have messages of different order at the various nodes. This gives us a further degree of freedom in terms of better code construction. Using the binary image of the parity check matrix, we define the function node which maps lower order messages to higher order and vice-versa. In order to have a reduced compexity decoder which is practically implementable, we use the truncated messages concept at the check nodes and evaluate its performance. We show improved performance in the error floor region as compared to other non-split low complexity decoding algorithms.","PeriodicalId":344018,"journal":{"name":"2009 6th International Symposium on Wireless Communication Systems","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125457175","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}