David S.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

Experience: Decades of experience in Digital Signal Processing at Bell Labs and derivative companies. Education: Masters degree in EE with emphasis in Digital Signal Processing, Adaptive Filtering and Digital Communications. Skills: - Algorithm design for radio signal analysis and reception targeted mostly at OFDM. - Design and implementation of complex algorithms for Audio and Data Communications signal processing. - Echo Cancellation of both Acoustic and electrical echoes. - Sub-band processing applied to acoustic signal processing problems including acoustic echo cancellation and noise reduction. - Design and implementation of Polyphase FIR filters for various application including sub-band decomposition and sample rate conversion. - All sorts of applications of Adaptive filtering including echo cancellation, system identification and sinusoidal interference reduction. - Design and implementation of Equalization for data communications mostly targeted at time domain QAM type signals. - Synchronization and timing recovery for data communications and for audio signals. - Extensive exposure to issues of audio and acoustics. - Good understanding of baseband data communications. - FSK, QPSK, DPSK and OFDM modulation techniques. - Good understanding of wireless communications. - Mathematical and Statistical understanding of signals and data. - C programming and some C++. - Matlab programming. - Algorithm design and implementation. - Systems design. - Simulations in MatLab and custom programming. - Windows, MAC and Unix/Linux. - Office tools like Word, Excel, PowerPoint etc. - Presentation skills and public speaking. - Learning R and Python. - Learning Software Designed Radio (SDR) processing techniques. - Learning Big Data techniques. - GIT, SVN. Products and projects: - Algorithmic development of complete receiver startup for burst modem communications for OFDM based communications, including carrier offset correction, timing selection and the beginnings of channel estimation and compensation. - Time domain and frequency domain analysis of OFDM signals used in LTE communications systems. - Multi-lateration of time of arrival signals for determining device positions from 4G and 5G radio signals. - Analysis of radio signals for reverse engineering digital communications at baseband. - Development of major DSP components for several modems from V.22 to V.90 used in AT&T, agere, LSI and Avago modem products and chipsets. - Software modules for full-duplex speakerphones used in many AT&T and NCR products. - Software modules for network echo cancellation sold by LSI to companies like Cisco for VoIP platforms. - Image processing software and hardware for label reading of the MaxiCode labels seen on most UPS packages. Patents: More than 15 patents awarded for various signal processing techniques used in modems, echo cancelers and some image processing applications. Please see my LinkedIn profile for further information, davidgshaw1.