Maximum likelihood sequence detection in the phase domain

1. A wireless device, comprising:

a receiver configured to receive a signal having in-phase and quadrature components;

a non-linear filter demodulator configured to translate noncoherently the in-phase and quadrature components into a phase domain signal;

a coherence acquisition unit configured to estimate and correct at least one coherence parameter based on the in-phase and quadrature components and the phase domain signal; and

a coherent detector configured to detect information in the phase domain signal.

2. The wireless device of claim 1 , further comprising:

an estimator configured to estimate a modulation index of the received signal; and

an equalizer configured to equalize the estimated modulation index to a predefined modulation index.

3. The wireless device of claim 2 , wherein the estimator is configured to perform a linear estimation technique for unknown linear coefficients.

4. The wireless device of claim 2 , wherein the predefined modulation index is about 0.5.

5. The wireless device of claim 2 , wherein the detector is a Maximum Likelihood Sequence Detector (MLSD).

6. The wireless device of claim 1 , wherein the nonlinear filter demodulator is based on a model comprising a plurality of sets of variables.

7. The wireless device of claim 6 , wherein the plurality of sets of variables comprise a set of auxiliary variables, a set of instantaneous frequency variables, and a set of instantaneous phase variables.

8. A wireless communication network comprising:

a first wireless device, which is the wireless device of claim 1 ; and

a second wireless device communicating with the first wireless device.

9. The wireless communication network of claim 8 , wherein the wireless communication network is a low-power wireless sensor and actor network (LP-WSAN), the first wireless device is an actor, and the second wireless device is a sensor.

10. A method of wireless communication, comprising:

receiving, by a receiver, a signal having in-phase and quadrature components;

translating noncoherently, by a non-linear filter demodulator, the in-phase and quadrature components into a phase domain signal;

estimating and correcting, by a coherence acquisition unit, at least one coherence parameter based on the in-phase and quadrature components and the phase domain signal; and

detecting, by a coherent detector, information in the phase domain signal.

11. The method of claim 10 , further comprising:

estimating, by an estimator, a modulation index of the received signal; and

equalizing, by an equalizer, the estimated modulation index to a predefined modulation index.

12. The method of claim 11 , wherein the estimating by the coherence acquisition unit is linear estimation for a plurality of unknown linear coefficients.

13. The method of claim 11 , wherein the predefined modulation index is about 0.5.

14. The method of claim 10 , wherein the detecting step is performed using Maximum Likelihood Sequence Detection (MLSD).

15. A computer program product embodied on a non-transitory computer-readable medium comprising program instructions configured such that when executed by processing circuitry cause the processing circuitry to implement the method of claim 10 .

16. A wireless device, comprising:

a receiving means for receiving a signal having in-phase and quadrature components;

a non-linear filtering demodulating means for translating noncoherently the in-phase and quadrature components into a phase domain signal;

a coherence acquisition means for estimating and correcting at least one coherence parameter based on the in-phase and quadrature components and the phase domain signal; and

a coherent detection means for detecting information in the phase domain signal.

17. The wireless device of claim 16 , further comprising:

an estimating means for estimating a modulation index of the received signal; and

an equalizing means for equalizing the estimated modulation index into a predefined modulation index.

18. The wireless device of claim 16 , wherein the detection means is a Maximum Likelihood Sequence Detector.