DIGITAL SIGNAL PROCESSING CONSIDERATIONS IN FILTER-CODEC TESTING.

Initially, transmission tests on a filter-codec have been performed with high precision analog instrumentation. However, one input and one output of the filter-codec is inherently in digital format: processing of samples of waveforms rather than continuous waveforms can be readily justified in the environment of today as well as of tomorrow. Several digital signal processing techniques are available to predict with required precision the filter-codec gain, phase, delay, harmonic, total, and intermodulation distortion, as well as the weighted idle noise. This paper discusses the algorithms, the results with measured and simulated data, and the lower bound time estimates on filter-codec transmission parameter tests, subject to stipulated signal to noise ratio and accuracy requirements.