Wireless Communication

Vishal Sharma ¹, Jaspreet Singh ¹

Affiliations
1 Shaheed Bhagat Singh State Technical Campus, Ferozepur, Punjab, IN

Abstract

An OFDM system is deliberated for various modulation schemes like BPSK, QPSK, 8PSK, 16PSK, QAM to uncover the preeminent permutation with OFDM technology. This work is carried out over the Rayleigh- and Rician-channels with additive white Gaussian noise (AWGN) for various normalized signal-to-noise ratio (SNR) values. Furthermore, number of errors measurement is also premeditated to assess the system performance along with the best combination to be used in wireless systems. The work simulated in this paper comes out with some new and brief results under different channel conditions. Our simulative results recommend BPSK+OFDM to be implemented to provide best spectral efficiency with an alternative of QPSK+OFDM under worst channel conditions for Rayleigh channels. For, Rician channels, BPSK is recommended under poor- and good- channel conditions. Under best channel conditions, BPSK and 8PSK outperforms. This work also present the impact of number of subcarriers over the BER of the system and has been revealed out that BPSK, QPSK and 8PSK offer better spectral efficiency by increasing number of subcarriers up to a certain level under best channels conditions for Rician channel.

Keywords

OFDM, SNR, BER, Digital Modulation Techniques.

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Vishal Sharma ¹, Navneet Kaur ¹

Affiliations
1 Department of Electronics & Communication, Shaheed Bhagat Singh State Technical Campus, Ferozepur, Punjab, IN

Abstract

Wimax, a next generation high-speed wireless access network provides larger coverage along with sting QoS and security mechanism compared to WiFi. In this paper, we have demonstrated QoS estimation of location based OFDM-Wimax access network and is followed by a comparison of performance of the reported OFDM-Wimax network at each location. The obtained simulative results prop up the influence of the position of MS home agent over performance of proposed Wimax network significantly. Further, the performance improvement due to incorporation of OFDM technology by reducing the fading problem in such wireless networks is reported. The proposed OFDM-Wimax access network achieved a prolonged coverage area with acceptable uplink and downlink SNR together with required BLER than that of conventional Wimax networks. The performance of proposed OFDM-Wimax network is evaluated with respect to QoS parameters such as throughput, average delay (Uplink/Downlink), end to end delay (Uplink/Downlink), packet jittering (Uplink/Downlink), SNR (Uplink/Downlink), BLER (Uplink/Downlink), and packet dropped (Uplink/Downlink).

Keywords

QoS, SNR, Wimax Network.

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Vishal Sharma ¹, Mandip Kaur ², Vijay Banga ², Harsukhpreet Singh ³

Affiliations
1 Shaheed Bhagat Singh College of Engineering and Technology, Ferozepur, Punjab, IN
2 Amritsar College of Engineering and Technology, Amritsar, Punjab, IN
3 Kapurthala, Punjab, IN

Abstract

Mobile Adhoc Networks (MANETs), a rapidly deployed wireless network that uses multi-hop routing instead of static network infrastructure to provide network connectivity, have received increasing research attention in recent years because of its vast applications in dynamic military and civilian systems. Variations with time in network topology impose new challenges for routing protocols in such networks as traditional routing protocols are not suitable for MANETs. Researchers are working together to design a new improved routing protocol by comparing and improving existing MANET‟s routing protocols before any routing protocol is standardized. In this paper, an effort has been made to ascertain the comprehensive performance evaluation of three commonly used mobile ad-hoc routing protocols such as Dynamic Source Routing (DSR), Temporally ordered routing algorithm (TORA) and Adhoc On-demand Distance-Vector Protocol (ADOV). Our works reports that the performance of different routing protocols varies according to different application situations as AODV performs better than TORA in high mobility situation while DSR outperforms in less stressful situations.

Keywords

AODV, DSR, MANET, TORA.

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