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US 8,077,757 B2Granted
Sampling method for a spread spectrum communication system
AssigneeQUALCOMM Incorporated
InventorsIrena Maravic, Martin Vetterli, Julius Kusuma
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Abstract
Method for decoding a signal sent over a bandwidth-expanding communication system, where both channel estimation and signal detection are carried out on a set of samples generated by sampling the received signal at a sub-Nyquist rate, thus allowing for a significant reduction of the complexity of the sampling device of receivers using said method, as well as a significant reduction of their computational requirements.
Claims66
Method for processing a signal (y(t)) sent over a wireless communication channel, comprising
- sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs))
- reconstructing the received signal (y(t)) using the set of sampled values (y(nTs)).
A non-transitory computer-readable medium on which is recorded a control program for a data processor, the computer-readable medium comprising instructions for causing the data processor to:
- sample a signal (y(t)) sent over a wireless communication channel with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said signal (y(t)), but greater than the rate of innovation (ρ) of said signal (y(t)), for generating a set of sampled values (y(nTs)) and
- reconstruct the received signal (y(t)) using the set of sampled values (y(nTs)).
An apparatus for processing a signal (y(t)) sent over a wireless communication channel, comprising:
- a receiver configured to sample the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs)) and to reconstruct the received signal (y(t)) using the set of sampled values (y(nTs)).
An apparatus for processing a signal, comprising:
- means for receiving a signal (y(t)) over a wireless communication channel;
- and
- means for sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs))
- means for reconstructing the received signal (y(t)) using the set of sampled values (y(nTs)).
1 more element
A mobile station for wireless communication, comprising:
- at least one antenna;
- and
- a receiver configured to receive a signal (y(t)) over a wireless communication channel via the at least one antenna, and sample the signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs)) and to reconstruct the received signal (y(t)) using the set of sampled values (y(nTs).
Method for processing a signal (y(t)) sent over a wireless communication channel, comprising:
- sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs))
- reconstructing the received signal (y(t)) using the set of sampled values (y(nTs)), wherein the step of reconstructing comprises, retrieving delays (τk(l)) and amplitude attenuations (ak(l)) induced by said communication channel on said sent signal (y(t)), from a set of spectral values (Y[m]) corresponding to said received signal (y(t)) and from spectral values (Sk[m]) corresponding to a user specific coding sequence (sk(t)).
Method for processing a signal (y(t)) sent over a wireless communication channel, comprising:
- sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs)), wherein said sent signal (y(t)) includes a plurality of training sequences (bkt) each encoded with a user specific coding sequence (sk(t)) and transmitted by said users (k), said method further comprising,
- reconstructing the received signal (y(t)) using the set of sampled values (y(nTs)), wherein the step of reconstructing comprises, computing a set of spectral values (Y[m]) corresponding to said received signal (y(t)) from said set of sampled values (y(nTs)), recovering spectral values (Sk[m]) corresponding to each of said user specific coding sequence (sk(t)), retrieving the delays (τk(l)) and the amplitude attenuations (ak(l)) induced by said communication channel on said sent signal (y(t)), from said set of spectral values (Y[m]) corresponding to said received signal (y(t)) and from said spectral values (Sk[m]) corresponding to each of said user specific coding sequence (sk(t)).
Method for processing a signal (y(t)) sent over a wireless communication channel, comprising:
- sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs)),
- reconstructing the received signal (y(t)) using the set of sampled values (y(nTs)), wherein the step of reconstructing comprises, retrieving delays (τk(l)) and amplitude attenuations (ak(l)) induced by said communication channel on said sent signal (y(t)), from a set of spectral values (Y[m]) corresponding to said received signal (y(t)) and from spectral values (Sk[m]) corresponding to a user specific coding sequence (sk(t)), wherein retrieving said delays (τk(l)) and said amplitude attenuations (ak(l)) includes solving a series of one-dimensional estimation problems, the size of each said one-dimensional estimation problem being equal to the number of said sampled values (y(nTs)) generated during one symbol duration (Tb).
Method for channel estimation comprising:
- sending a signal over an channel to be estimated;
- receiving the sent signal (y(t));
- determining the rate of innovation (ρ) of said received signal (y(t));
- sampling the received signal (y(t)) with a sampling frequency (fs) lower than the sampling frequency given by the Shannon theorem, lower than the chip rate (1/Tc) of said received signal (y(t)), but greater than the rate of innovation (ρ) of said received signal (y(t)), for generating a set of sampled values (y(nTs))
- using the set of sampled values (y(nTs)) to estimate the channel.
2 more elements
Dependencies are inferred from the claim text.