Abstract

This paper focuses on the electromagnetic radiation from various emblematic cellular mobile base stations in the urban, semi urban and rural locations. Theoretical assessment of radiofrequency exposure due to cellular base station antennas is treated. The estimation of the Electric field with reference to macro cell towers Installation is derived. From the electric field thus evaluated, magnetic field and power density are determined. Finally, the received power is calculated for the given power density, receiver antenna gain and frequency of the cell towers.

The electric field, magnetic field, power density and radiated power are calculated for the different effective radiated powers, with different operating frequencies, and with distance ranging of 10 meters to 600 meters. The theoretical analysis of the field intensities of the radiation emitted from the RF source, and thus computing radiated power levels at various distances from the RF source, helps in estimating the radius of zone where the radiation level is hazardous.

Abstract

FIR filters are widely used in wireless mobile communication systems such as channel equalization, matched filtering, and pulse shaping, due to their stability and reconfigurability. In this paper, the pulse shaping FIR filter such as root-raised cosine filter is designed for multistandard digital up converter. The two bit binary common sub-expression based binary common sub-expression elimination algorithm is used to ignore the occurrences in identical bit pattern. The number of additions and multiplications are reduced using this technique. Carry save adder is used to generate the partial product which reduces the area and increases the speed. The area and speed of the filter design is synthesized and simulated using Xilinx ISE 12.1.

Abstract

The objective of this paper is to present Underwater Communication technique that provides uninterrupted and reliable service in shallow water for MIMO application. Acoustic sensor network is based on combination of Interleave-division multiple access (IDMA) and orthogonal frequency division multiplexing (OFDM), the OFDM is a modulation technique where signal splits into multiple sub-signals and simultaneously transmitted at different frequencies to the receiver. IDMA is an alternative of Code Division Multiple Access (CDMA) that distinguishes each user with the unique random interleaver code. The OFDM- IDMA is imperial design for reducing error bursts that occur in multi-access underwater applications. The authors have implemented above techniques for Multiple Inputs Multiple Outputs (MIMO), to transfer more data using same bandwidth at the same time, therefore technique is known as MIMO-OFDM-IDMA. MIMO-OFDM-IDMA which is a new concept, having the capability of high rate transmission and robustness against multi-path fading and other channel impairments. The results of MIMO-OFDM-IDMA have been analyzed with theory and simulation.

Abstract

Two receiver architectures for equalization of multi-h continuous phase modulation (CPM) are presented. In the first technique, the receiver front end is a matched-filter bank, which is obtained from Laurent decomposition of the signal. In the circulant-matrix model, samples of the matched filter are used to perform the equalization in frequency domain. The second technique employs a receiver with a simple front end consisting of a low-pass filter and a fractional sampler. Acirculant matrix model for the latter approach is devised, which relates the Laurent pseudo-symbols to each polyphase component at the output of the sampler. In this paper, delta modulation can simulate both analog and digital signals, during reception the noise will be removed by using Gaussian filter. In this method, turbo coding is used to increase the data rate in mobile communication.

Abstract

This paper proposes the development of advanced audio recording techniques for airborne fighter aircrafts as many fighters are currently using audio tape recorders which are causing lots of inconvenience for the storage and analysis. This paper provides guidelines for the design and development of electronic system for defence applications. Currently verities of electronics devices are commercially available with modern technologies but not mature for defence application, because it required rigorous qualification testing to work under specified MIL conditions. This paper proposes an advanced Hardware and software designs with Mpeg 1 layer III audio coding and compression for defence applications by replacing tape recorder. This paper provides an in depth theory behind hardware requirement and the MPEG-1 Layer III standard, which is useful for implementation of a Digital Audio Recorder. The authors have developed and simulated the proposed concept using Matlab and found the audio quality satisfactory for airborne application