Energy saving in Analog to Digital Convertors: how Multi-Coset Non Uniform sampling scheme can help
Résumé
The ever-growing increase of frequency bandwidths of telecommunications systems have been putting a huge constraint on Analog to Digital Convertors (ADC). This constraint originates from the Shannon-Nyquist sampling law: to prevent any overlap sampling have to be performed at the Shannon-Nyquist rate which has to equal at least twice the transmitted bandwidth. As a result, the larger the bandwidth, the higher the sampling frequency and the higher the energy consumption of the ADCs. To cope with this issue, especially in non-contiguous bandwidths (ie no full bands containing holes [2] – one would refer to sparse signal spectrums), one solution is to use non uniform sampling schemes (NUSS) what makes possible the update of the sampling frequency according to the spectral occupancy rate. Given the Multi-Coset (MC) NUSS this paper proposes an original criteria (namely AliasMin mode) to lower the spectrum side lobes of signals when using NUSS. Following this idea, it is shown that the sampling frequency of ADCs can be updated according to the spectrum occupancy rate (ie sparsity rate) to mitigate the energy consumption of ADCs.