Method for bandpass sampling by position modulated wavelets
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsMichael Pelissier, Marguerite Marnat
Life of this patent
Estimating the term…
Abstract
The present invention relates to a wavelet bandpass sampling method, with low aliasing and a corresponding device. The analogue signal to sample is correlated with a sequence of wavelets succeeding each other with a rate fp of which the positions in the sequence are temporally modulated from arguments of a CAZAC sequence, notably a Zadoff-Chu sequence. The correlation results are next sampled at a frequency fs≤fp and digitally converted to provide a compressed representation of the signal. The temporal modulation of the positions of the wavelets makes it possible to obtain incoherent aliasing of the correlation signal in the sampling band and thereby to reduce aliasing.
Claims14
A method for bandpass sampling of an analogue signal, the spectrum of said signal having a set of sub-bands, said signal being correlated with a sequence of wavelets succeeding each other with a rate fp equal to the sum of the widths of said sub-bands, the central frequencies of the wavelets belonging to said sub-bands, the method comprising:
- temporally modulating the respective positions of the wavelets in the sequence by means of arguments of successive elements of a Constant Amplitude Zero AutoCorrelation waveform (CAZAC) sequence, the correlation results with the sequence of wavelets thereby position modulated being sampled with a frequency fs≤fp and digitally converted.
A device for bandpass sampling of an analogue signal by bandpass sampling, the spectrum of said signal having a set of sub-bands, the device including at least one sampling branch comprising:
- a wavelet sequence generator, the wavelets of said sequence succeeding each other with a rate fp equal to the sum of the widths of said sub-bands;
- a correlator for correlating the analogue signal with said sequence of wavelets and supplying correlation results at the rate fp;
- a sampler for sampling the correlation results at the rate fp;
- an analogue digital converter for decimating and digitally converting the correlation results thereby sampled;
- and
- a temporal position modulator intended to modulate the temporal positions of the wavelets of the sequence of wavelets generated by the generator, before correlation with the analogue signal, the temporal modulation being carried out by means of arguments of successive elements of a Contact Amplitude Zero AutoCorrelation waveform (CAZAC) sequence.
Dependencies are inferred from the claim text.