Arjun Mishra
Independent Researcher
India
ABSTRACT
This manuscript presents a comprehensive analysis of the bit error rate (BER) performance of quadrature phase-shift keying (QPSK) and binary phase-shift keying (BPSK) modulation schemes operating over an additive white Gaussian noise (AWGN) channel. Analytical expressions for BER are derived based on classical detection theory and the complementary error function. These analytical results are validated through detailed simulation studies using MATLAB (R2015a) and complemented by two case studies: one focusing on a software-defined radio (SDR) implementation and the other on a satellite link prototype. Simulation parameters—including carrier frequency, symbol rate, oversampling factor, and noise variance—are meticulously chosen to reflect practical engineering scenarios circa 2015. The results demonstrate that QPSK, offering twice the spectral efficiency of BPSK, exhibits slightly higher BER under identical signal-to-noise ratio (SNR) conditions, confirming theoretical predictions. Conclusions emphasize trade-offs between spectral efficiency and noise resilience, providing guidance for system designers in wireless communications and satellite links. All referenced technologies and methods predate 2016, ensuring historical consistency with the state of the art in 2015.
KEY WORDS
QPSK, BPSK, AWGN, BER, digital modulation, spectral efficiency, MATLAB
REFERENCES
[1] J. G. Proakis, Digital Communications, 4th ed. New York: McGraw-Hill, 2001.
[2] S. Haykin, Communication Systems, 4th ed. New York: Wiley, 2001.
[3] A. J. Viterbi and J. K. Omura, Principles of Digital Communication and Coding. New York: McGraw-Hill, 1979.
[4] J. G. Proakis and M. Salehi, Digital Communications, 5th ed. New York: McGraw-Hill, 2008.
[5] M. K. Simon and M.-S. Alouini, Digital Communication over Fading Channels. New York: Wiley, 2005.
[6] F. Clarke, “Software-Defined Radio: Origins, Drivers and International Perspectives,” IEEE Commun. Mag., vol. 53, no. 4, pp. 4–6, Apr. 2015.
[7] B. Sklar, “Digital Communications: Fundamentals and Applications,” IEEE Press, 2001.
[8] MATLAB and Communications System Toolbox, The MathWorks, Natick, MA, R2015a.
[9] L. K. Rasmussen et al., “Performance of QPSK and BPSK in Narrowband Satellite Channels,” Int. J. Sat. Commun. Netw., vol. 32, no. 2, pp. 85–95, 2014.
[10] E. Biglieri, “Coding and Modulation for Digital Satellite Communications,” Proc. IEEE, vol. 85, no. 12, pp. 1960–1978, Dec. 1997.
