No description available.

<p>Using more than just on antenna can significantly speed up the data rate in a wireless communication system. These systems are commonly referred to as Diversity- and MIMO-systems. Due to tight volume restriction for the antennas, e.g. in a mobile phone, electromagnetic coupling between the antennas will degrade the capacity of the wireless system and lower the coverage.</p><p><p>In the proposed thesis, a thorough study of Ethertronics’ standard antennas will be established in which the antennas will be used in a multiport system, e.g. MIMO. The thesis will be strongly related to Ethertronics’ engagement in Chase and therefore also dependent on the latest progresses on MPA (Multiport Analyzer) developed in Chase. The thesis will result in a working methodology how to use MPA plus design-, location- and orientation rules for the standard antennas used in a multiport system.</p></p>

Using more than just on antenna can significantly speed up the data rate in a wireless communication system. These systems are commonly referred to as Diversity- and MIMO-systems. Due to tight volume restriction for the antennas, e.g. in a mobile phone, electromagnetic coupling between the antennas will degrade the capacity of the wireless system and lower the coverage. In the proposed thesis, a thorough study of Ethertronics’ standard antennas will be established in which the antennas will be used in a multiport system, e.g. MIMO. The thesis will be strongly related to Ethertronics’ engagement in Chase and therefore also dependent on the latest progresses on MPA (Multiport Analyzer) developed in Chase. The thesis will result in a working methodology how to use MPA plus design-, location- and orientation rules for the standard antennas used in a multiport system.

<p>In the high-end research process of wireless systems and in the race for the development of the new technologies, MIMO (Multiple Input, Multiple Output) is getting more attention now days. It has a high potential usage in the 3G and 4G communications and beyond. The MIMO based system has got the ability to increase the data throughput in spectrum-limited conditions. With the increase and complexity of wireless applications, the spectrum efficiency improvement in the physical layer will be saturated. MIMO is predicted to be one of the major features for the next generation wireless networking. This thesis work is a part of an ongoing project of the Generic MIMO decoder design carried out at the research laboratory, LESTER at Lorient, France. I was involved in the study of MIMO concepts, orthogonal and Space-time codes and later involved in the design and optimization of the architecture for the core operator for the ML decoder used in the reception of the MIMO system,which is presented in this report work.</p>

This paper considers the combination of interference alignment and distributed antenna systems to improve the rate performance of cell-edge users in the cellular downlink. Because the power resources of each antenna in distributed antenna systems are geographically separated, practical implementations of distributed antenna systems require consideration of per-antenna power constraints on the transmit antennas. For this reason, we consider interference alignment with two types of power constraints: per-antenna power inequality constraints and per-antenna power equality constraints. On one hand, we show that interference alignment with per-antenna power inequality constraints is arbitrarily feasible using a technique of antenna power back-off but suffers from a loss of performance that we quantify in the case of Rayleigh-fading. On the other hand, we show that interference alignment with per-antenna power equality constraints does not suffer from a systematic loss of performance but yet requires more antennas to be feasible. We develop algorithms for implementing interference alignment with both types of constraints and numerically validate the results of our analysis. Finally, we demonstrate using the 3rd Generation Partnership Project spatial channel model in a cellular setting that interference alignment with distributed antenna systems has better rate performance than interference alignment with centralized antenna systems throughout the entire cell, especially near the cell boundary. / text

In the high-end research process of wireless systems and in the race for the development of the new technologies, MIMO (Multiple Input, Multiple Output) is getting more attention now days. It has a high potential usage in the 3G and 4G communications and beyond. The MIMO based system has got the ability to increase the data throughput in spectrum-limited conditions. With the increase and complexity of wireless applications, the spectrum efficiency improvement in the physical layer will be saturated. MIMO is predicted to be one of the major features for the next generation wireless networking. This thesis work is a part of an ongoing project of the Generic MIMO decoder design carried out at the research laboratory, LESTER at Lorient, France. I was involved in the study of MIMO concepts, orthogonal and Space-time codes and later involved in the design and optimization of the architecture for the core operator for the ML decoder used in the reception of the MIMO system,which is presented in this report work.

(Thesis: M.Sc.Eng.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / In recent years, the effects of process variation have become increasingly more severe as technology has been scaling down in lithographic dimension. This problem also has affected the operation of the MINS IC (Multi-Input Neural Sensor) designed at Boston University by Dr. Lu Wang. This MINS chip was designed for use in both in-vitro and in-vivo applications of measuring and recording neural action potentials and local field potentials in the brains of animals. The MINS chip has been tested and is fully functional, however, with a serious problem of output level shifting from input-to-input due to process variation. This thesis will focus on the study of the effect of process variation on the MINS chip and a proposed method for process variation correction. The effect of process variation on the MINS chip is an extremely serious issue, given the large amount of gain required to sense and record neural signals, especially local field potentials, which have an input voltage of the order of 10-100 μV. The previous version of the printed circuit board designed to correct for process variation can center the output between the upper and lower rails by measuring the required column bias current independently for each of 256 inputs individually and storing these on an FPGA. However, this process variation correction procedure has jeopardized the ability to scan at the required rate in order to record action potentials (spikes). This thesis has two parts: The first part includes the study of the effects of process variation on the functionality of the 8HP MINS chip by doing Gaussian distribution analysis. The second part is the design of a new printed circuit board to increase the speed of the process variation correction procedure in scan mode, and as a goal, to center the output level in both stop mode and scan mode. The study of the effects of process variation on MINS utilizes circuit simulations with the IBM 8HP device models and design kit, using extracted models based on the MINS chip layout. According to the Monte Carlo sampling analysis, only 12 out of 200 samples are showing output level to be around center, with 65% of the samples having output voltage at upper and lower rails. What is more, as the study of 1000 cases shows, a column bias current of about 105uA and/or a bias voltage of 1.212 V, with 3σ to be 3.798uA and 0.131V respectively, is needed to center the output. A new developed version of the variation correction PCB has been designed and fabricated, utilizing a charge pump methodology to quickly charge up (or discharge) the large stabilization capacitor (4.7μF) placed on the Ibias0 node for stability, on the existing MINS PCB. Given that the Ibias0 current on MINS is only around 100μA, a large current of the order of 250-500mA is used in order to achieve the desired scan rate on the chip. A ping-pong approach is used, having two 4.7μF capacitors so that one can be readied while the other is being used for the testing. This PCB design also includes the needed controls with comparators and logic to terminate the charging/discharging operation at the exact correct voltage on the Ibias0 node, for each of the 256 inputs. On this new board, the required voltage at the Ibias0 node (Vbias0) to center the output, instead of Ibias0, will be measured and stored for each of 256 inputs in both stop mode and scan mode. / 2031-01-01

No description available.

In the thesis, we use the concept of single-negative metamaterials to reduce the antennas¡¦ coupling. Firstly, the multilayer insulator is proposed to enhance the isolation bandwidth. The isolation bandwidth is broadened by adjusting the individual layer of insulators with close but different operating frequencies. Then, the designed multilayer insulator is inserted in a planar antenna system. Isolation of the MIMO antenna system is below than -20dB. The measured and simulated isolation bandwidth is 8% and 6.9%, respectively. We then design dual-band insulators for dual-band MIMO antenna applications. The proposed dual-band insulator is implemented bystacking the insulators with different operating bands and the isolation of the dual-band MIMO antenna can be improved at both 2.6 and 3.5GHz bands. In the broadband insulator design, the T-shaped branch is proposed to broadenthe operating bandwidth. The measured isolation bandwidth is improved by 12.8% than that of the multilayer insulator. The bandwidth of the proposed broadband insulator can be used in other broadband communication standards.

abstract: A Multi-input single inductor dual-output Boost based architecture for Multi-junction PV energy harvesting source is presented. The system works in Discontinuous Conduction Mode to achieve the independent input regulation for multi-junction PV source. A dual-output path is implemented to regulate the output at 3V as well as store the extra energy at light load condition. The dual-loop based sliding-mode MPPT for multi-junction PV is proposed to speed up the system response time for prompt irradiation change as well as maximize MPPT efficiency. The whole system achieves peak efficiency of 83% and MPPT efficiency of 95%. The whole system is designed, simulated in Cadence and implemented in PCB platform. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2017