The last three decades have seen significant advances in the wireless communication field. As the data rates of wireless systems are increasing, the demand for mobile services also is increasing rapidly. Like other natural resources, radio spectrum suitable for mobile wireless communications is also limited. In order to keep up with this ever increasing demand, there is a requirement of new signal processing algorithms. Diversity is a technique used in wireless systems to combat the effects of fading and thereby improve reliability of data transfer. There are many ways in which algorithms can exploit diversity in wireless channels. Hybrid-automatic repeat request (H-ARQ) schemes and relaying mechanisms are two such diversity extracting techniques. Even though these diversity achieving techniques have been well understood in theory, there are many ways in which one can optimize these techniques for specific application scenarios.In this thesis, we focus on improving the performance of retransmission schemes and relaying systems. In the first part of the thesis, we improve the performance of H-ARQ schemes in the 3GPP- long term evolution (LTE) system by improving the performance of feedback signaling. We employ complex-field coding to extract the inherent frequency diversity available in the resources. Next, we provide a sub-optimal solution to the outage-optimal power allocation problem in incremental redundancy based H-ARQ system, whose performance is practically the same as that of the optimal solution. In the later part of the thesis, we propose a retransmission scheme based on superposition coding (SPC) for the symmetric relaying scenario. We provide packet error probability (PEP) expressions and solutions for the optimal fraction of power allocated for the partners' data. Finally, we study the optimal bits-to-symbol mappings for SPC and its effect on an H-ARQ scheme and the symmetric relaying scenario using SPC.

<p>IP-based TV (IPTV) is gradually replacing traditional means for broadcasting. At the same time, players from the telecom industry is seeking to create a new, standardized architectural framework for delivering all kinds of multimedia services over IP to end users; the IP Multimedia Subsystem (IMS).</p><p>This thesis is about video on demand, one of the more popular services enabled by IPTV. The thesis starts out by introducing the reader to IMS and IPTV and presents the current work in the area of IMS-based IPTV, done by the TISPAN committee of the ETSI.</p><p>The author then takes an explorative approach in investigating how a signaling schema for an IMS-based VOD service could look like, based on TISPAN’s existing work. The service is subject to an extra requirement; it should support session continuity, meaning it should be possible to resume the streaming of a video where the user left off, possibly on a different device. The investigation shows that it is possible to combine SIP and RTSP in several ways to get the desired behaviour.</p><p>The second part of the results consists of a proof of technology-implementation of the signaling schema that is the output from the first part. The implemented service runs on an IPTV set-top box on the client side, and a regular PC on the server side. The service uses open source software to a great extent and is fairly portable. A sample VOD session using the implemented system is presented along with full message contents.</p><p>The thesis concludes with a summary of the results and a discussion on what has been left out from the implementation and possibly subject to further studies. Finally, there is a brief summary on the recent developments within the field of IMS-based IPTV.</p>

IP-based TV (IPTV) is gradually replacing traditional means for broadcasting. At the same time, players from the telecom industry is seeking to create a new, standardized architectural framework for delivering all kinds of multimedia services over IP to end users; the IP Multimedia Subsystem (IMS). This thesis is about video on demand, one of the more popular services enabled by IPTV. The thesis starts out by introducing the reader to IMS and IPTV and presents the current work in the area of IMS-based IPTV, done by the TISPAN committee of the ETSI. The author then takes an explorative approach in investigating how a signaling schema for an IMS-based VOD service could look like, based on TISPAN’s existing work. The service is subject to an extra requirement; it should support session continuity, meaning it should be possible to resume the streaming of a video where the user left off, possibly on a different device. The investigation shows that it is possible to combine SIP and RTSP in several ways to get the desired behaviour. The second part of the results consists of a proof of technology-implementation of the signaling schema that is the output from the first part. The implemented service runs on an IPTV set-top box on the client side, and a regular PC on the server side. The service uses open source software to a great extent and is fairly portable. A sample VOD session using the implemented system is presented along with full message contents. The thesis concludes with a summary of the results and a discussion on what has been left out from the implementation and possibly subject to further studies. Finally, there is a brief summary on the recent developments within the field of IMS-based IPTV.

The recent increase of mobile data usage and emergence of new applications such as Online Gaming, mobile TV, Web 2.0, Streaming Contents have greatly motivated the 3rd Generation Partnership Project (3GPP) to work on the Long Term Evolution (LTE). The LTE is the latest standard in the mobile network technology tree. It inherits and develops the GSM/EDGE and UMTS/HSPA network technologies and is a step toward the 4th generation (4G) of radio technologies designed to optimize the capacity and speed of 3G mobile communication networks. In this thesis, the LTE system capacity and coverage are investigated and a model is proposed on the base of the Release 8 of 3GPP LTE standards. After that, the frequency planning of LTE is also studied. The results cover the interference limited coverage calculation, the traffic capacity calculation and radio frequency assignment. The implementation is achieved on the WRAP software platform for the LTE Radio Planning.

Long Term Evolution (LTE) constitutes a significant milestone in the evolution of 3G systems towards fourth generation (4G) technologies. The performance targets promised by LTE makes it an ideal solution to accommodate the ever increasing demand for wireless broadband. LTE's promised performance targets were made possible due to improvements such as a simplified system access architecture and a fully IP-based platform. LTE has also great enhancements in its enabling radio technologies by introducing Orthogonal Frequency Division Multiplexing (OFDM) and advanced antenna technologies. In addition, LTE capabilities are further improved with enhanced Quality of Service (QoS) support for multiple data services, such as voice and other multimedia applications. LTE packet scheduling plays an essential role as part of LTE's Radio Resource Management (RRM) to enhance the system's data rate and to support the diverse QoS requirements of mobile services. LTE packet scheduler should intelligently allocate radio resources to mobile User Equipments (UEs) such that the LTE network adheres to its performance requirements. In our work, we perform a performance evaluation of multiple LTE scheduling algorithms proposed for LTE uplink transmission. The evaluation takes place in single and mixed traffic scenarios to exploit the strengths and weaknesses of proposed algorithms. Simulation results illustrated the importance of a scheduler's awareness of uplink channel conditions and QoS requirements in the presence of single and multiple traffic scenarios. Accordingly, we provide recommendations for future scheduling algorithm proposals, and ways to enhance the existing schedulers. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-05-07 12:43:54.983

3GPP is in the process of enumerating functionality for Access Network Discovery and Selection Function (ANDSF). The ANDSF includes data management and control functionality which are essential for providing network discovery and selection function to the User Equipment (UE, MS, mobile station) w.r.t. operators’ policy. A lack of quantitative measures of ANDSF benefits was identified so our task is to identify these benefits. The aim of the thesis is to present ideas for how to obtain such measures and we develop a tool which implements (some of) these ideas and finally we have examples of possible results which will support such a discussion with numbers. This report also discusses different number of use case scenarios (such as ANDSF and USER) which we implement in our simulation tool. In our simulation model we use to impose preferred strategy, reduced delays and losses, and system utilization efficiency. One more thing likes to clarify that the numbers which we use in our model are just examples. It can be any number but they will give us the same behavior of learning. Providing real gains is outside the scope of our study. / The aim of the thesis is to identify quantitative measures of ANDSF benefits. Our contribution is to develop ideas for how to obtain such measures in order to identify ANDSF benefits. We developed a simulation tool which implements some of these ideas. In simulation tool we impose preferred strategies, reduced delays and losses and work on system utilization efficiency in order to identify ANDSF benefits. In our simulation model we use different implementation terminologies like network traffic, access networks, and preferences w.r.t. quality as well as w.r.t. strategies. We have two main scenarios ANDSF and USER; we also perform extensive comparative study in order to evaluate analysis of gains from ANDSF. We have examples of possible results and our numbers are just examples because providing real gains is outside our study. We evaluate our scenarios w.r.t. three main aspects; how well the strategies are fulfilled? How many attempts are required for users? and compare blocking probabilities. The overall conclusion of the thesis is to find out the reasons that why ANDSF is a better choice for network selection as compare to users themselves. Our results shows that ANDSF is a better option for network selection because it helps users towards use their service efficiently as well as avoid blocking; even in real environment the ANDSF becomes aware of less congested access networks in the area the UE is located, and provides instructions to the UE to move the existing IP flows to the less congested access network. / +46762173562

Future generation cellular networks are expected to deliver an omnipresent broadband access network for an endlessly increasing number of subscribers. Long term Evolution (LTE) represents a significant milestone towards wireless networks known as 4G cellular networks. A key feature of LTE is the implementation of enhanced Radio Resource Management (RRM) mechanism to improve the system performance. The structure of LTE networks was simplified by diminishing the number of the nodes of the core network. Also, the design of the radio protocol architecture is quite unique. In order to achieve high data rate in LTE, 3rd Generation Partnership Project (3GPP) has selected Orthogonal Frequency Division Multiplexing (OFDM) as an appropriate scheme in terms of downlinks. However, the proper scheme for an uplink is the Single-Carrier Frequency Domain Multiple Access due to the peak-to-average-power-ratio (PAPR) constraint. LTE packet scheduling plays a primary role as part of RRM to improve the system’s data rate as well as supporting various QoS requirements of mobile services. The major function of the LTE packet scheduler is to assign Physical Resource Blocks (PRBs) to mobile User Equipment (UE). In our work, we formed a proposed packet scheduler algorithm. The proposed scheduler algorithm acts based on the number of UEs attached to the eNodeB. To evaluate the proposed scheduler algorithm, we assumed two different scenarios based on a number of UEs. When the number of UE is lower than the number of PRBs, the UEs with highest Channel Quality Indicator (CQI) will be assigned PRBs. Otherwise, the scheduler will assign PRBs based on a given proportional fairness metric. The eNodeB’s throughput is increased when the proposed algorithm was implemented.

No / Software radio and reconfigurable systems represent reconfigurable functionalities of the radio interface. Considering turbo decoding function in battery-powered devices like 3GPP mobile terminals, it would be desirable to choose the optimum decoding algorithm: SOVA in terms of latency, and log-MAP in terms of performance. In this paper it is shown that the two algorithms share common operations, making feasible a reconfigurable SOVA/log-MAP turbo decoder with increased efficiency. Moreover, an improvement in the performance of the reconfigurable architecture is also possible at minimum cost, by scaling the extrinsic information with a common factor. The implementation of the improved reconfigurable decoder within the 3GPP standard is also discussed, considering different scenarios. In each scenario various frame lengths are evaluated, while the four possible service classes are applied. In the case of AWGN channels, the optimum algorithm is proposed according to the desired quality of service of each class, which is determined from latency and performance constraints. Our analysis shows the potential utility of the reconfigurable decoder, since there is an optimum algorithm for most scenarios.

<p>Efficient radio resource management is of paramount importance for achieving the high bit rates targeted by the 3GPP for the 3GPP Long-Term Evolution. The radio air interface must be able to provide both high peak bit rates and acceptable cell-edge bit rates. This thesis therefore investigates three methods which try to combine the peak bit rate of a reuse-1 system with the cell-edge bit rate of a reuse-3 system in an OFDM-based downlink. These methods are soft frequency reuse, reuse partitioning and one variation of soft frequency reuse, reuse-1 with prioritization.</p><p>In static simulations with one user per cell and a system load of 100 percent, a Shannon capacity gain of up to 18 percent at the 10th percentile is shown with reuse partitioning compared to a reuse-1 system. This gain comes coupled with a loss of only 5 percent at the median. Soft frequency reuse is also investigated statically and shows a 13 percent gain at the 10th percentile compared to a reuse-1 system. Having a lower 10th percentile gain than reuse partitioning, it also shows a slightly smaller loss of 4 percent at the median and a much smaller loss at the 90th percentile.</p><p>Dynamic simulations with a traffic model and multiple users per cell offer a more realistic scenario and show that the proposed intercell interference management methods do not provide the same throughput gains in the dynamic case at low system loads. If interference is not an issue, interference coordination is still costly in terms of limiting bandwidth and/or decreasing the scheduling gain, but provides no significant interference reduction. At low system loads, reuse-1 is therefore the best scheme although interference coordination might prove necessary to provide edge-user throughput at high loads. For such purposes, soft frequency reuse is shown to be a potential candidate and although not investigated in a dynamic setting, reuse partitioning is believed to have similar performance. The traffic model chosen in this thesis only allows study of low system loads but at these loads, soft frequency reuse performs promisingly close to a reuse-1 system.</p>

Efficient radio resource management is of paramount importance for achieving the high bit rates targeted by the 3GPP for the 3GPP Long-Term Evolution. The radio air interface must be able to provide both high peak bit rates and acceptable cell-edge bit rates. This thesis therefore investigates three methods which try to combine the peak bit rate of a reuse-1 system with the cell-edge bit rate of a reuse-3 system in an OFDM-based downlink. These methods are soft frequency reuse, reuse partitioning and one variation of soft frequency reuse, reuse-1 with prioritization. In static simulations with one user per cell and a system load of 100 percent, a Shannon capacity gain of up to 18 percent at the 10th percentile is shown with reuse partitioning compared to a reuse-1 system. This gain comes coupled with a loss of only 5 percent at the median. Soft frequency reuse is also investigated statically and shows a 13 percent gain at the 10th percentile compared to a reuse-1 system. Having a lower 10th percentile gain than reuse partitioning, it also shows a slightly smaller loss of 4 percent at the median and a much smaller loss at the 90th percentile. Dynamic simulations with a traffic model and multiple users per cell offer a more realistic scenario and show that the proposed intercell interference management methods do not provide the same throughput gains in the dynamic case at low system loads. If interference is not an issue, interference coordination is still costly in terms of limiting bandwidth and/or decreasing the scheduling gain, but provides no significant interference reduction. At low system loads, reuse-1 is therefore the best scheme although interference coordination might prove necessary to provide edge-user throughput at high loads. For such purposes, soft frequency reuse is shown to be a potential candidate and although not investigated in a dynamic setting, reuse partitioning is believed to have similar performance. The traffic model chosen in this thesis only allows study of low system loads but at these loads, soft frequency reuse performs promisingly close to a reuse-1 system.