The development of the transistor and its continuous down-scaling has allowed during the last decades the appearance of cheap wireless communication systems targeting consumer products. The complexity of these systems has increased dramatically during the last years, mainly fueled by both the Moore law and improvements in communication theory. Originally, the radio transceivers were composed of only a few transistors, and supported simple analog modulation schemes. Currently, radio transceivers are composed of thousands of transistors including not only radio/analog blocks but also a huge amount of digital circuitry as well. These radios use advanced digital modulation schemes, channel coding, and multiple access schemes. Despite the fact that digital circuits currently offer an impressive performance, pure digital signal processing of radio signals remains limited for relatively low frequencies below a few hundred MHz. On the other hand, frequency bands used in current mobile applications span from around 800MHz up to 6 GHz and hence demand the use of analog circuits to down-convert the radio signals to lower frequencies that are suitable for digital processing. The group of circuits that form this part of the receiver is known as the radio receiver front-end. The design of modern radio receiver front-ends has many challenges. One requirement is support of a multitude of standards with bands that are scattered all along the mobile radio spectrum. Accordingly, the noise and linearity specifications for these front-ends are very stringent. Also, these specifications have to be accomplished using low-power, low-cost, highly integrated circuit solutions. This thesis presents the design of multi-band multi-standard receiver front-ends for fourth generation mobile communications. A novel methodology that speeds up the development of multi-band multi-standard RF blocks by automating some steps in the design is shown. Examples of submicron and nanometer CMOS wideband receiver front-ends targeting 4G mobile applications are presented. New techniques for inductorless wideband front-ends using current-mode technology are presented. Finally, novel RF calibration techniques to cope with process, voltage, and temperature variations in modern CMOS processes are demonstrated. / QC 20100806 / RaMSiS

This thesis presents an investigation of the impact of indoor small-cells. It is expected that small-cells will be able to increase the throughput and capacity for the existing networks. A deployment algorithm is presented with focus on offloading traffic from the macro layer. The performance of the deployments created with the proposed algorithm, is compared with a reference deployment. The different deployments are then simulated in a real network simulator, which performs static simulations in 3 dimension using the theory of multiple knife-edge diffraction. The small-cells increased the throughput and capacity remarkably and additional gains were obtained with the proposed algorithm. The thesis also includes strategies for small-cell deployment.

Design of the next generation (4G) systems is one of the most active and important area of research and development in wireless communications. The 2G and 3G technologies will still co-exist with the 4G for a certain period of time. Other applications such as wireless LAN (Local Area Network) and RFID are also widely used. As a result, there emerges a trend towards integrating multiple wireless functionalities into a single mobile device. Low noise amplifier (LNA), the most critical component of the receiver front-end, determines the sensitivity and noise figure of the receiver and is indispensable for the complete system. To satisfy the need for higher performance and diversity of wireless communication systems, three LNAs with different structures and techniques are proposed in the thesis based on the 4G applications. The first LNA is designed and optimized specifically for LTE applications, which could be easily added to the existing system to support different standards. In this cascode LNA, the nonlinearity coming from the common source (CS) and common gate (CG) stages are analyzed in detail, and a novel linear structure is proposed to enhance the linearity in a relatively wide bandwidth. The LNA has a bandwidth of 900MHz with the linearity of greater than 7.5dBm at the central frequency of 1.2GHz. Testing results show that the proposed structure effectively increases and maintains linearity of the LNA in a wide bandwidth. However, a broadband LNA that covers multiple frequency ranges appears more attractive due to system simplicity and low cost. The second design, a wideband LNA, is proposed to cover multiple wireless standards, such as LTE, RFID, GSM, and CDMA. A novel input-matching network is proposed to relax the tradeoff among noise figure and bandwidth. A high gain (>10dB) in a wide frequency range (1-3GHz) and a minimum NF of 2.5dB are achieved. The LNA consumes only 7mW on a 1.2V supply. The first and second LNAs are designed mainly for the LTE standard because it is the most widely used standard in the 4G communication systems. However, WiMAX, another 4G standard, is also being widely used in many applications. The third design targets on covering both the LTE and the WiMAX. An improved noise cancelling technique with gain enhancing structure is proposed in this design and the bandwidth is enlarged to 8GHz. In this frequency range, a maximum power gain of 14.5dB and a NF of 2.6-4.3dB are achieved. The core area of this LNA is 0.46x0.67mm2 and it consumes 17mW from a 1.2V supply. The three designs in the thesis work are proposed for the multi-standard applications based on the realization of the 4G technologies. The performance tradeoff among noise, linearity, and broadband impedance matching are explored and three new techniques are proposed for the tradeoff relaxation. The measurement results indicate the techniques effectively extend the bandwidth and suppress the increase of the NF and nonlinearity at high frequencies. The three proposed structures can be easily applied to the wideband and multi-standard LNA design.

Actualmente, más de la mitad de habitantes de nuestro país: 15,4 millones de peruanos, son usuarios de Internet móvil, lo que nos demuestra que estamos frente ante un servicio prioritario para la mayoría de la población, que nos permite el revisar el correo desde el celular, actualizar las redes sociales en cualquier momento, descargar música o ver videos ya no son actividades propias de tres de cada diez ciudadanos, sino que en un año pasamos a 51% de penetración y dentro de cuatro años serán siete de cada 10 los internautas móviles y tres de ellos, según Cisco, usarán redes 4G LTE. Las conexiones vía 4G LTE hoy son usadas por aproximadamente cuatro millones de peruanos, los costos de los equipos y los planes de datos que la ofrecen suelen ser un poco más elevados que las generaciones anteriores (3G o 2G), sin embargo, su tendencia para ser adquirida es imparable gracias a que se trata de una tecnología idónea en términos de velocidad de transmisión de datos que genera navegar en Internet, según explica el catedrático de la UPC, Carlos Valdez. Por lo que señalo como un obstáculo en estos momentos, la deficiente infraestructura para soportar la gran demanda de los usuarios, la no existencia de un plan de inversiones que nos permita contar con un servicio adecuado en los próximos años, si sigue creciendo el número de usuarios y los avances de uso de esta tecnología 4G sobretodo en los lugares más alejados de la Región Junín.

This diploma thesis focuses on the telecommunications field and specifically on the analysis of the Czech telecommunications market. Theoretical part of the thesis is focused on the historical development of telecommunications in terms of technological trends in the world and their subsequent transfer to Czech market. The practical part deals with the analysis of the Czech market, according to selected criteria, particularly in terms of privided services, their quality and technological solutions. The emphasis is on the analysis of operation of the mobile telecommunication and data services providers in the Czech Republic. The result of this diploma thesis is the analysis of the current state of the Czech telecommunications market in common with positive forecasts.

The number of wireless connected devices are growing exponentially and the importance of this research area is growing as well to meet the known and looming challenges and expectations. The 5:th Generation telecommunications standard is partly embodied by the Machine-to-Machine (M2M) and Internet of Things (IoT) technologies and standards to handle a big part of these devices and connections. An example within the IoT paradigm is military training systems where each system can consist of thousands of battery operated mobile devices and their shifting requirements shall be fullled in an energy-aware manner to increase battery operating times. Military training radio networks enables realistic combat training. The services and features provided in commercial telecommunications networks are desirable in these often proprietary and task specic networks, increasing capabilities and functionalities. To facilitate the current and future R&D of LTE based networks for adoption in military training networks and services this doctoral thesis intends to provide the starting ground for the energy-aware LTE based wireless communications. The thesis first presents general solutions on how to meet traffic deadlines in wireless networks for large number of nodes, and then continues with solutions for energy-aware LTE-based communications for the User Equipments (UEs). The work builds on the problem formulation how to provide energy-aware resource handling for LTE-based military training networks from where three research questions are derived. From the research questions we derive different hypotheses and then test these within the investigated area to answer the research questions. The contributions of this work are within areas of resource handling and power saving for mobile devices. In the first area an admission control using deterministic analysis is proposed fullling traffic requirements for military training mobile nodes. This admission control is enhanced for multiple-channel base stations, and evaluated using mobile nodes with different heterogeneous traffic requirements. In the second part energy-awareness is in focus for LTE/LTE-A based networks. The main power saving method for LTE/LTE-A UEs, Discontinuous Reception (DRX) mechanism, is evaluated and models for DRX in Idle and Connected state are proposed including metrics for wake-up delay and power saving. Additionally a mean queuing delay analysis is proposed for a variant of the Connected state DRX. Using these models and metrics, practical design guidelines for tuning of DRX parameters are proposed, including optimization of DRX parameters for either minimizing delay or maximizing power saving.

Mobile communication is developing very rapidly with passage of time, new technologies are being introduced to facilitate the mobile users more from the technology. The past technologies are replaced by new ones and needs are growing for the new technologies to be developed. One such development is fourth generation networks. Also called future generation or Next Generation Networks. The introduction of 4G has widened the scope of mobile communication. Now mobile is not only a device used for talking but its more or less a portable computer that can serve different purposes. 4G offers higher data rates with seamless roaming. The mobile user can communicate without any disturbance while switching his coverage network. 4G is still passing through research and therefore there are some problems that need to be fixed in order to benefit the users from it fully. In this report we discuss various challenges 4G is facing and solutions to those problems are discussed. We propose our own way of improving QoS in 4G by using combination of mobility protocol SMIP and SIP. We propose that by using such scheme we can achieve better QoS during the process of handover. / Mobil kommunikation utvecklas mycket snabbt med tiden, är ny teknik införs för att underlätta mobilanvändare mer av tekniken. Det förflutna teknik ersätts av nya och behov ökar för ny teknik som skall utvecklas. En sådan utveckling är fjärde generationens nät. Kallas även kommande generationen eller nästa generations nät. Införandet av 4G har räckvidden för mobil kommunikation. Nu mobil är inte bara en enhet som används för att prata, men dess mer eller mindre en bärbar dator som kan tjäna olika syften. 4G erbjuder högre dataöverföringshastigheter med sömlös roaming. Den mobila användaren kan kommunicera utan störningar samtidigt som du slår sin täckning nätverk. 4G är fortfarande passerar genom forskning och därför finns det vissa problem som behöver rättas till för att gynna användarna av den helt. I denna rapport diskuterar vi olika utmaningar 4G står inför och lösningar på dessa problem diskuteras. Vi föreslår vårt eget sätt att förbättra QoS i 4G genom kombination av mobilitet protokoll SMIP och SIP. Vi föreslår att genom att använda ett sådant system som vi kan uppnå bättre QoS under processen för överlämnandet. / 0044788479520

In this day and age, with highly available and fast networks, many tasks are being performed remotely. However, certain tasks cannot be flawlessly executed remotely, for instance, the tasks performed by professional drivers. Their jobs demand a lot of visual cues, fast actions, and low response times, which is difficult in particular when task execution is performed wirelessly. With the release of 5G, which promises to deliver reliable and rapid response times with URLLC, high bitrates with eMBB, and supports a massive number of devices with mMTC, many companies and researchers are trying to investigate if 5G is an enabler for wireless control of commercial vehicles. This thesis first examines the latency requirements for remote control operations, and then see how 5G can meet those requirements. In this respect, the thesis discovers the latency thresholds without affecting the control performance in a scenario with users operating a small robot. Then, various tests were performed using a trial 5G system to evaluate its performance in terms of latency, video quality, bandwidth, and signal strength. In controlling robot experiments, the results showed that the highest acceptable cycle latency, both for accurate maneuvering and satisfying operator experience, is around 154ms. These results were then used as a benchmark in the tests conducted using a 4G public network and a single-cell 5G network. These tests revealed that 5G could deliver lower latencies, higher bitrates, and similar video quality when compared to 4G. However, it was difficult to retain good signal quality over 5G, especially when roaming in non-line-of-sight propagation areas. This behavior is as expected due to the terminal’s association with a single 5G base station, which can be easily mitigated with denser deployments.

Yes / In this work, a compact 4-element multiple-input multiple-output (MIMO) antenna system is presented for sub-6 GHz applications. A modified M-shaped strip is used to form each antenna element in the MIMO system. To improve performance, a rectangular-shaped area is etched on the opposite side of each element in the ground plane. The antenna size is 100 × 60 mm2. Most interestingly, the port isolation is improved by rotating the etched areas and the corresponding radiating elements. This one-of-a-kind approach aided in the development of a highly isolated MIMO antenna with a small footprint. The theory of characteristic modes (TCM) is used to analyze the behavior of rotating the etched areas in the ground of the antenna. The antenna provides significant port isolation above 20 dB, stable radiation patterns, and an outstanding ECC of less than 0.01. The design is simple and compact, making it suitable for MIMO operation on handheld devices.

The purpose of this thesis is to explore the concept of resource scheduling and pricing and its relation to carrier aggregation. The first main topic is a modified Frank Kelly algorithm that allows for the use of utility functions that are piecewise concave, but not a member of a strictly \'diminishing return\' model. This adjustment to the Frank Kelly algorithm allows resource allocation to take into account devices with multiple applications. The second topic introduces the idea of scheduling resources in a carrier aggregation scenario assuming the carriers are scheduled sequentially. / Master of Science