Evaluation of High Speed Hardware Multipliers - Fixed Point and Floating point

There is a huge demand in high speed arithmetic blocks, due to increased performance of processing units. For higher frequency clocks of the system, the arithmetic blocks must keep pace with greater requirement of more computational power. Area and speed are usually conflicting constraints so that improving speed results mostly in larger areas. In our research we will try to determine the best solution to this problem by comparing the results of different multipliers. Different sized of two algorithms for high speed hardware multipliers were studied and implemented ie. Parallel multiplier, Bit serial multiplier. The workings of these two multipliers were compared by implementing each of them separately in VHDL. A number of high speed adder designs are developed and algorithm and design of these adders are discussed. The result of this research will help us to choose the better option between serial and parallel multipliers for both fixed point and floating point multipliers to fabricate in different systems. As multipliers form one of the most important components of many systems, analysing different multipliers will help us to frame a better system with area and better speed.DOI:http://dx.doi.org/10.11591/ijece.v3i6.418

SAW Filter Modelling in Matlab for GNSS Receivers

Satellite navigation has enabled a great amount of new application for many users, but a lot of limitations have been observed regarding precision and integrity of navigation signals. Overall signals of different navigation systems (GPS, GALILEO, GLONASS signals) compose Global Navigation Satellite Systems (GNSS) Signal. Each of the satellite system has separate signal characteristics, but each signal needs to be compatible with the others to prevent interferences and attenuations between signals. The processing of all the signals is performed in same receiver. Hence, complex receiver design is required. In GNSS signals different frequencies are used for different satellite navigation systems such as GPS, Galileo and Glonass. When the group delay response is observed in SAW filters it shows that the signals lie on different frequencies have different delays. Manufacturers carried out measurements with respect to carrier wave but they have ignored the spreading codes or modulation. In this research, we will design a model for GNSS SAW filter in Matlab. This model can be use to obserce the delay of the signals. This model will allow the manufacturers to address these problems in the SAW filter software to optimise slope and magnitude of the design which will benefit the users of GNSS all over the world to get more precise positioning.DOI:http://dx.doi.org/10.11591/ijece.v3i5.364

Design and Simulation of Cascaded Class-A Microwave Power Amplifier

Microwave power amplifiers are the most significant components in wireless communications systems. As the technology continue to progress, the designers are facing new challenges and opportunities. The purpose of this work is to push the limits of efficiency and bandwidth of power amplifiers. The objective of this research is to design and build a prototype two stage Microwave power amplifier operated at 2.4 GHz with a linear region of operation up to our desired output of 0.5 watt or 27 dBm. The transistor used in the first stage is BFP540 while the output power of the first stage is the input of the second stage in which the ATF50189 transistor is used to for amplification. All the simulations and readings are taken by using AWR Microwave Office software. By using the load line Rl and the biasing points are achieved for both stages. The applications of our proposed device include many products in the field of microwave communications. One of the important applications of a Microwave power amplifier is in the output stage of a transmitter where a signal needs amplification before it is transmitted.DOI:http://dx.doi.org/10.11591/ijece.v3i5.364

A Systematic Approach to Generate 3D Path Loss Heat Maps for WIFI Indoor Positioning

To estimate the location of an object in an indoor environment, many indoor positioning techniques have been developed in recent decades. The popularity of indoor positioning systems has increased nowadays to enable the implementation of indoor location-based services. WIFI-based fingerprinting is one the most promising techniques to estimate the user or robot’s location in an indoor environment. Fingerprinting-based indoor positioning systems require the laborious task of environmental surveys to generate the fingerprinting database. This calibration process of a fingerprinting database causes the adaptability problem due to the high cost of the survey of the WIFI environment. Researchers have proposed different techniques to minimize the survey cost by means of the automatic generation of a fingerprinting database and its calibration. Most of these techniques only generate 2D path loss heat maps, while ignoring the height information of transmitting and receiving devices. In this paper, a systematic approach is presented to generate 3D path loss heat maps in which height information is also incorporated in the generation of more realistic 3D heat maps. The results show that the proposed technique for 3D environment generation outperformed the existing techniques, and the root mean square error (RMSE) is 2.17. Moreover, the proposed technique generated 3D heat maps effortlessly and its accuracy is almost equivalent to the real maps