FPGA-based signal averaging added to digitiser feature set

July 08, 2014 // By Graham Prophet
Using FPGAs, Spectrum has created new firmware packages that allow its high-speed M4i series digitiser cards to perform on-board signal averaging. The M4i.44xx series cards offer real-time sampling rates of up to 500 Msamples/sec with 14 bit resolution and 250 Msamples/sec with 16 bit resolution.

German company Spectrum designs and manufactures PC-based test and measurement instrumentation for electronic signal capture, generation and analysis, specialising in high-speed digitiser and generator technology. The new averaging package features ultrafast performance being able to acquire and average signals at rates of over 5,000,000 events per second. The M4i series cards are available with two or four channels and, thanks to the cards fast PCIe bus, acquired and averaged data can be transferred directly to a host PC at speeds of up to 3.4 GB/sec.

Signal averaging is a time domain based processing technique that is used to reduce the random noise component of a signal, improving its signal-to-noise ratio (SNR), while at the same time increasing a digitiser's measurement resolution and dynamic range. Ideally, if the signal and noise are uncorrelated, the noise being random while the signal is repetitive, then the averaging function can improve the SNR in proportion to the square root of the number of measurements (or averages). For example, averaging a signal 256 times may improve the SNR by as much as 24 dB or increase measurement resolution by about 4 bits.

The averaging option (-spavg) is available now on the M4i.44xx series of PCIe high-speed digitisers as well as on the Ethernet/LXI digitiser product of the digitiserNETBOX DN2.44x.

Spectrum Systementwicklung Microelectronic; http://spectrum-instrumentation.com/en/news/block-average-firmware