Authors: Abhay Samant; Sandeep Kumar Yadav; Venkataramana Badarla; Shirish Mishra
Addresses: Center for ICT, IIT Jodhpur, Rajasthan, India ' Center for ICT, IIT Jodhpur, Rajasthan, India ' Center for ICT, IIT Jodhpur, Rajasthan, India ' Center for ICT, IIT Jodhpur, Rajasthan, India
Abstract: The impact of signal-to-noise ratio (SNR) of an additive white Gaussian noise (AWGN) channel on bit error rate (BER) has been extensively studied in the literature through theoretical, simulation-based, and experimental results. However, it is too simplistic to assume that BER in a real-world communication system is influenced by AWGN alone. The system's radio, which contributes both linear and nonlinear impairments, also impacts BER. This paper studies the impact of linear impairments, namely quadrature skew and gain imbalance, on the BER of an angular digital modulation scheme, such as M-ary phase shift keying (M-PSK). It presents a mathematical derivation of a technique to measure these impairments. It implements this technique on an experimentation system and presents statistical properties of these measurements. A novel contribution of this paper is a cross layer protocol through which the receiver shares these measured values with the transmitter. The transmitter uses this information to combat the effects of radio's impairments on BER, thereby improving system performance. This paper also presents a cost benefit analysis which proves that the idea proposed in this paper is feasible and practical to implement on real-world systems.
Keywords: cross layer design; gain imbalance; quadrature skew; radio front end; throughput; USRP.
International Journal of Information and Communication Technology, 2017 Vol.11 No.2, pp.202 - 221
Received: 08 Jul 2014
Accepted: 12 Oct 2014
Published online: 11 Aug 2017 *