Low cost back end signal processing driven bandwidth interleaved signal acquisition using free running undersampling clocks and mixing signals

As communication data rates increase, wideband signals are being increasingly used to accommodate high rates of information transmission. Acquiring and characterizing the time domain waveform of such signals requires high measurement system sampling rate and wide input bandwidth and is thus, expensive. A key problem that drives up the cost of traditional bandwidth interleaved data acquisition systems is the need to synchronize the input signal (periodic) with the sampling clock as well as the oscillator inputs to all the mixers in the band interleaved architecture. This synchronization problem is complicated at multi-GHz frequencies and increases overall design cost. In this paper, we propose a low-cost band-interleaved architecture that uses: (a) incoherent undersampling to acquire the signal across the frequency bands of the band-interleaved system and (b) does not require any mutual synchronization between the input signal, the undersampling clocks and the mixing signals (local oscillators) of each frequency band in the band-interleaved system. The reconstruction is achieved through back-end spectrum analysis and use of signal processing algorithms that compensate for the lack of synchronization. The proposed technique is supported by hardware validation experiments.