Channeliser IP core features expanded for complex comms analyses in FPGA

February 23, 2016 // By Graham Prophet
RFEL is adding features to the latest version of its ChannelCore Flex advanced channeliser IP core, ChannelCore Flex. It continues to provide highly versatile, solutions for demanding channelisation applications such as communications, intercept, electronic warfare, security, industrial applications, COMINT, SIGINT, sonar, radio astronomy, research and software-defined radio.

There is now the option of VITA 49 compatible precision time-stamping of the output channelised data. This time-stamping is provided to 5 nsec accuracy or better. The core receives time-stamped ADC data and provides a dynamic, compensated time-stamp with the output data for each channel.

The input stage has been enhanced, now with support for up to four inputs giving improved application flexibility. An input buffer provides flow control for supporting network sourced baseband data. The input sample rate and FPGA clock rate are decoupled with the maximum aggregate output channel sample rate now limited to the FPGA clock rate. A front-end frequency mixer stage allows for global frequency correction on each input channel, to counter effects such as Doppler, for example, to accuracies much lower than 1 Hz.

ChannelCore Flex uses a novel architecture to implement a large number of Digital Down Converter (DDC) channels very efficiently. FPGA resources are used in proportion to the log of the number of channels enabling thousands of channels to be implemented in a moderately sized FPGA.

Real-time, on-the-fly control is available for each channel to change the input source selection, centre frequency, sample rate, gain and filter response including bandwidth. New in this latest release is the user programmable option to maintain phase coherency when reprogramming channels and the core is still capable of being phase coherent across multiple cores.

Each channel path is normalised to map a full-scale input signal to half the dynamic range on the output giving output headroom, and an internal gain stage provides up to 102 dB of gain per channel, which is adjustable at run-time. Each channel has excellent RF performance with SFDR of greater than 80 dBc, 80% Nyquist pass-band and a passband ripple of less than 0.1 dB. The user can select either an Infinite Impulse Response (IIR) or the Finite Impulse Response (FIR) output filter stage to provide more effective filter response with reduced resource utilisation.