Digital modulation scheme in four dimensions based on wavelets

Abstract

Information transmission over noisy channels in an efficient and reliable way is a primary objective of digital communication. In this article we propose a digital modulation scheme with a signal space of four dimensions to increase reliability. The signal space of this scheme is constructed on an orthonormal wavelet basis and its constellation is shaped by the eight farthest vertices of a hypercube centered on origin. For decisions based on minimum Euclidean distance, the proposed modulation scheme overcomes the performance against noise of that of quaternary quadrature amplitude modulation (4-QAM). This result allows us to say that a suitable design of constellation over a signal space with more than two dimensions can achieve a reduction in the bit error rate without a significant reduction of spectral efficiency.