Search for: All records

This paper proposes a post-experimental field data reuse method to test the single carrier modulation (SCM) and orthogonal frequency division multiplexing (OFDM) signals interchangeably for multiple access underwater acoustic (UWA) communications. We call this approach the cross evaluation that transforms a set of SCM or OFDM post-experimental field data to their corresponding OFDM or SCM scheme under test (SUT) via linear matrix operation such as fast Fourier transform (FFT) and its inverse (IFFT). At the receiver side, we derived a general framework of turbo equalization (TEQ) that alters the two physical layer schemes but keeps the passband transmitted and received data unchanged. Inherently, some efficient techniques such as pre-cursor and post-cursor interference cancellation (IC), and overlap adding (OLA) operations enhance the equivalence of input and output (I/O) system model between the SCM and OFDM. The proposed approach will bring the gap between the SCM and OFDM, and evaluate the two physical layer schemes under similar or tougher test conditions. The experimental results of the undersea 2008 Surface Processes and Acoustic Communications Experiment (SPACE08) have verified the feasibility of the cross evaluation approach in terms of the BER benchmark.