Arbitrary Waveform Generators for synthetic instrumentation

Generating nonlinear modulation with minimum memory requirements

“…An analysis of the performance of the original system of Fig. 1 may be found in [1], [2]. The modifications to this system to support nonlinear modulation add a second input source to the Farrow Structure.…”

“…1, developed in [1], [2], can be made to support nonlinear modulation. All that is needed is an integrator and sin/cos computation.…”

“…Carrier generation is readily accomplished in a real-time, resource efficient manner using a Numerically Controlled Oscillator (NCO). A block diagram of the AWG from [1] is given in Fig. 1.…”

“…The new input source is the complex envelope of a nonlinearly modulated signal. In order to control interpolation image distortion, the bandwidth of the complex envelope must be taken into consideration when designing the interpolation system (see [1], [2] for further details).…”

“…If pulse-shaping is performed in real-time, only the symbols need to be stored in memory at the symbol rate. This is taken advantage of by modern AWGs for the case of linear digital modulation [1]- [4]. In this contribution it is shown how a high performance AWG can be designed allowing the same memory compression and increased waveform playback time for the important class of nonlinear digital modulation schemes.…”