• Windowed Sinc Filter Factory in C++

    As part of my ongoing research I have been developing a receiver structure. I moved it to C++ for speed after initial experiments using Matlab. Part of the receiver structure includes lowpass and bandpass signal filters that were still using coefficient values printed from a Matlab designed filter using the fir1 command.

  • Thesis structure and style using LaTeX

    There are many ways to go about writing a thesis and many tools for doing so: MS Word, EndNote, LaTeX, BibTeX, the list goes on. As colleagues regularly use LaTeX for reports, papers, and originally on their own PhD theses there is much more collective experience than for MS Word in this area. LaTeX also benefits from the ability to use version control systems such as Git and Subversion as all the source files are essentially plain-text.

  • A centralised reference paper system using JabRef

    Before I get stuck into building the thesis I need a system for organising the references so that as the number of reference papers rapidly grows I will still be able to easily cite, locate, and annotate them.

  • Signal and Receiver Design for Low-Power Acoustic Communications Using M-ary Orthogonal Code Keying

    Abstract: Low-power, low received signal-to-noise-ratio (SNR) signals have potential for reducing the impact on marine life from acoustic communications. Here we explore the use of bandlimited pseudo-noise m-ary orthogonal code keying (M-OCK) scheme using m-sequences. Analysis and simulation of receiver structure for synchronisation and data demodulation performance is carried out. Performance of M-OCK is compared with m-ary quadrature amplitude modulation with direct-sequence spread-spectrum (M-QAM DSSS). Real-world channel experiments are carried out with transmission power for the M-OCK sequences limited to less than 1 W acoustic power (170.8 dB re 1 μPa at 1 m) and transmission range varied from 100 m to 10 km in the North Sea. Synchronisation at 10 km is achieved with effective received signal-to-noise-ratio of less than -9.96 dB, and data demodulation of 140.7 bit/s raw throughput with pre-coding bit-error-rate (BER) 0.5 × 10-1 (symbol-error-rate (SER) 0.1) and 46.9 bit/s raw throughput with pre-coding BER 0.9 × 10-3 (SER 1.95 × 10-3). Error-free synchronisation and data demodulation is achieved at ranges up to 2 km, demonstrating data rates in excess of 140 bit/s.