TSW4100

Hello,

The GC5016 can be operated in DDC or DUC modes.  There are several different modes of operation, within one device, or as on the TSW4100 there are 2 devices,

one DDC and one DUC.  The DDC&DUC Fundamentals application note, online GC5016 training, Guide for Using cmd5016, and the GC5016 datasheet can be used

to determine the operating modes.  There is a PFIR and CIC for the filtering and decimation/interpolation. 

Related to the TSW4100, the decimation ratio and interpolation ratio are common across the repeater channel.  The repeater can be operated in 4 channel mode, or splitIQ 2 channel modes.  SplitIQ means that I and Q are processed in separate DDC/DUC channels.  This increases the number of PFIR taps available.   

There is no direct Matlab model for the GC5016, there is a set of functional models that provide for

    Cascade Integrator Comb decimation and interpolation

    PFIR decimation and interpolation

The cmd5016 program will need to be run with the desired splitIQ, cic_dec, cic_int, pfir_dec, pfir_int ratios to determine the allowed number of PFIR taps.

DDC

    Complex Mixer

    CIC dec

    PFIR dec

    BB Gain (bbAGC is not supported in model equivalent)

DUC

    BBGain

    PFIR interp

    CIC interp

    Complex Mixer

    Channel summer (1 to 4 channels, and scaling) - not supported in model equivalent

The attached script creats a convolved response of the PFIR filter, CIC and allows the user to observe the spectral response of the filter.   The CIC response is estimated in the matlab script.   In the matlab script, there are 2 DDC examples, and 2 DUC examples, 1 DDC 4chan, 2 DDC splitIQ, 3DUC 4chan, 4DUC splitIQ

The GC5016 datasheet has the calculation of the number of clocks, the cmd5016 tool also has a calculation for the number of taps.  Once you input the cic_dec, cic_int

pfir_dec, pfir_int, the clock rate, Fs (filter stop half bandwidth), Fp (filter pass half bandwidth), the script can compute the convolved response of the GC5016 filter, and generate the PFIR taps to be used with cmd5016 to program the GC5016.

Note: the Matlab script requires the Signal Processing Toolbox to generate the filter taps.

Regards,

Radio Joe