Half bit correlator combining for data demodulation
A method for demodulating a data signal according to one embodiment includes processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. A system for demodulating a data signal according to one embodiment includes a correlator module having logic for: processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. Additional systems and methods are also presented.
1. A method for demodulating a data signal, the method comprising:
processing baseband signals using multiple complex correlators each having a half-Tbit length, wherein Tbit is the length of data bit;
summing outputs of the multiple complex correlators for a first data state; and
differencing outputs of the multiple complex correlators for a second data state.
2. The method of claim 1 , wherein each of the complex correlators includes a delayed integrator and a nondelayed integrator.
3. The method of claim 1 , wherein the summed outputs are kept separate until after outputs of complex-to-magnitude modules.
4. The method of claim 1 , wherein each of the complex correlators includes a series of windowed integrators that are configurable for different lengths.
5. The method of claim 1 , further comprising generating a correlator magnitude signal, and further comprising using the correlator magnitude signal to determine an end of a signal modulation.
6. The method of claim 1 , further comprising generating a correlator magnitude signal, and further comprising using the correlator magnitude signal to adjust an automatic gain control setting.
7. The method of claim 1 , further comprising generating a correlator magnitude signal, and further comprising using the correlator magnitude signal to derive a received signal strength indicator estimate.
8. The method of claim 1 , wherein the baseband signals are derived from a Miller modulated signal or a signal having bi-phase-space (FM0) encoding.
9. The method of claim 1 , wherein the first data state corresponds to a data 1, wherein the second data state corresponds to a data 0.
10. The method of claim 1 , wherein the first data state corresponds to a data 0, wherein the second data state corresponds to a data 1.
11. A system for demodulating a data signal, the system comprising:
a correlator configured to:
process baseband signals using multiple complex correlators each having a half-Tbit length, wherein Tbit is the length of data bit;
sum outputs of the multiple complex correlators for a first data state; and
difference outputs of the multiple complex correlators for a second data state.
12. The system of claim 11 , wherein each of the complex correlators includes a delayed integrator and a nondelayed integrator.
13. The system of claim 11 , wherein the summed outputs are kept separate until after outputs of complex-to-magnitude modules.
14. The system of claim 11 , wherein each of the complex correlators includes a series of windowed integrators that are configurable for different lengths.
15. The system of claim 11 , further comprising generating a correlator magnitude signal, and further comprising logic for using the correlator magnitude signal to determine an end of a signal modulation.
16. The system of claim 11 , wherein the baseband signals are derived from a Miller modulated signal or a signal having FM0 encoding.
17. The system of claim 11 , further comprising at least one antenna for receiving a radio frequency signal from which the baseband signals are derived.
18. The system of claim 11 , further comprising logic for generating a correlator magnitude signal, and further comprising logic for using the correlator magnitude signal to adjust an automatic gain control setting.
19. The system of claim 11 , further comprising logic for generating a correlator magnitude signal, and further comprising logic for using the correlator magnitude signal to derive a received signal strength indicator estimate.
20. The system of claim 11 , wherein the first data state corresponds to a data 1, wherein the second data state corresponds to a data 0.
21. The system of claim 11 , wherein the first data state corresponds to a data 0, wherein the second data state corresponds to a data 1.