Fault detection and correction by sum-signal modulation in 5G or 6G
A faulted 5G/6G message may be recovered by finding the faulted message elements and altering them until the fault is corrected. Disclosed are methods to evaluate the modulation quality of each message element using multiple criteria. The receiver can determine a first quality by measuring the overall (sum-signal) amplitude and phase of each message element, and comparing to the predetermined amplitude and phase levels. The receiver can determine a second quality by separating the overall wave into orthogonal components (branches) and comparing the branch amplitudes to the predetermined levels. The receiver can determine a third quality according to the SNR of the overall signal and the two branch signals. By combining the first, second, and third quality factors, the receiver can identify the most likely faulted message elements. The receiver can then alter the worst message elements in a nested grid search to find the correct message version.
1. A method for a wireless receiver to demodulate a wireless message, the method comprising:
a) receiving a message comprising message elements, each message element comprising an I branch signal multiplexed with an orthogonal Q branch signal, wherein each signal, of the I branch signal and the Q branch signal, is modulated according to a first plurality of predetermined branch amplitude levels;
b) determining, according to an error-correction code associated with the message, that the message is corrupted;
c) for each message element, determining a sum-signal comprising the I branch signal added to the Q branch signal, and determining a sum-signal amplitude and a sum-signal phase of the sum-signal; and
d) for each message element, determining a modulation quality by:
i) comparing the sum-signal amplitude to a second plurality of predetermined sum-signal amplitude levels; and
ii) comparing the sum-signal phase to a third plurality of predetermined sum-signal phase levels.
2. The method of claim 1 , wherein the message is received according to 5G or 6G technology.
3. The method of claim 1 , further comprising, for each message element:
a) determining a sum-signal amplitude deviation comprising the sum-signal amplitude minus a closest sum-signal amplitude level of the second plurality;
b) determining a sum-signal phase deviation comprising the sum-signal phase minus a closest sum-signal phase level of the third plurality; and
c) calculating a sum-signal modulation quality according to a combination of the sum-signal amplitude deviation and the sum-signal phase deviation.
4. The method of claim 3 , wherein, for each message element:
a) the sum-signal modulation quality is inversely related to a square root of a sum of the sum-signal amplitude deviation squared plus the sum-signal phase deviation squared.
5. The method of claim 3 , wherein, for each message element:
a) the sum-signal modulation quality is inversely related to a sum of a magnitude of the sum-signal amplitude deviation plus a magnitude of the sum-signal phase deviation.
6. The method of claim 3 , the method further comprising, for each message element:
a) determining an I branch amplitude according to the I branch signal, and determining a Q branch amplitude according to the Q branch signal;
b) determining an I branch deviation comprising a difference between the I branch amplitude and a closest predetermined branch amplitude level of the first plurality;
c) determining a Q branch deviation comprising a difference between the Q branch amplitude and a closest predetermined branch amplitude level of the first plurality; and
d) determining a branch modulation quality according to a combination of the I branch deviation and the Q branch deviation.
7. The method of claim 6 , wherein, for each message element:
a) the branch modulation quality is inversely related to a square root of a sum of the I branch deviation squared plus the Q branch deviation squared.
8. The method of claim 6 , wherein, for each message element:
a) the branch modulation quality is inversely related to a sum of a magnitude of the I branch deviation plus a magnitude of the Q branch deviation.
9. The method of claim 6 , further comprising, for each message element:
a) determining a first signal-to-noise ratio (SNR) value of the sum-signal, a second SNR value of the I branch signal, and a third SNR value of the Q branch signal; and
b) determining a SNR modulation quality inversely related to a combination of the first, second, and third SNR values.
10. The method of claim 9 , wherein, for each message element:
a) the modulation quality of the message element is inversely related to a combination of the sum-signal modulation quality, the branch modulation quality, and the SNR modulation quality.
11. Non-transitory computer-readable media in a wireless receiver, the media containing instructions that when implemented in a computing environment cause a method to be performed, the method comprising:
a) receiving a message comprising message elements, each message element modulated according to a modulation scheme, the modulation scheme comprising a sum-signal amplitude and a sum-signal phase, wherein each sum-signal amplitude is modulated, by a transmitter, according to integer Namp predetermined amplitude levels, and each sum-signal phase is modulated, by the transmitter, according to integer Nphase predetermined phase levels;
b) determining, according to an error-detection code associated with the message, that the message as received is corrupted;
c) for each message element of the message as received, determining a modulation quality according to a combination of an amplitude displacement and a phase displacement, wherein the amplitude displacement comprises a difference between the sum-signal amplitude and a closest predetermined amplitude level of the Namp predetermined amplitude levels, and the phase displacement comprises a difference between the sum-signal phase and a closest predetermined phase level of the Nphase predetermined phase levels.
12. The non-transitory computer-readable media of claim 11 , the method further comprising:
a) selecting a particular message element having a lowest modulation quality;
b) altering the sum-signal amplitude or the sum-signal phase, or both, of the particular message element; and
c) determining whether the message, including the alteration, is corrupted.
13. The non-transitory computer-readable media of claim 12 , wherein:
a) the altering the sum-signal amplitude comprises assigning one of the predetermined amplitude levels, other than the closest predetermined amplitude level, to the particular message element; and
b) the altering the sum-signal phase comprises assigning one of the predetermined phase levels, other than the closest predetermined phase level, to the particular message element.
14. The non-transitory computer-readable media of claim 11 , wherein:
a) for each message element, the modulation quality is inversely related to a square root of a sum of the amplitude displacement squared plus the phase displacement squared.
15. The non-transitory computer-readable media of claim 11 , wherein:
a) for each message element, the modulation quality is inversely related to a sum of a magnitude of the amplitude displacement plus a magnitude of the phase displacement.
16. A wireless receiver comprising signal processing electronics and a processor, the wireless receiver configured to:
a) determine, according to a demodulation reference, using the signal processing electronics, a first plurality of predetermined sum-signal amplitude modulation levels and a second plurality of predetermined sum-signal phase modulation levels;
b) receive, using the signal processing electronics, a message comprising message elements, each message element modulated according to a modulation scheme, the modulation scheme comprising, for each message element of the message, an I branch signal multiplexed with an orthogonal Q branch signal;
c) for each message element, using the signal processing electronics, measure an I branch amplitude of the I branch signal and a Q branch amplitude of the Q branch signal;
d) for each message element, using the processor, determine a sum-signal comprising a sum of the I branch signal plus the Q branch signal, and determine a sum-signal amplitude and a sum-signal phase of the sum-signal;
e) for each message element, using the processor, determine a sum-signal amplitude deviation comprising a difference between the sum-signal amplitude of the message element and a closest sum-signal amplitude level of the first plurality, and determine a sum-signal phase deviation comprising a difference between the sum-signal phase of the message element and a closest sum-signal phase level of the second plurality; and
f) for each message element, using the processor, determine a sum-signal modulation quality according to a combination of the sum-signal amplitude deviation and the sum-signal phase deviation.
17. The wireless receiver of claim 16 , further configured to:
a) determine, according to the demodulation reference, using the signal processing electronics, a third plurality of branch amplitude levels of the modulation scheme;
b) for each message element, determine an I branch deviation comprising a difference between the I branch amplitude and a closest branch amplitude level of the third plurality, and determine a Q branch deviation comprising a difference between the Q branch amplitude and a closest branch amplitude level of the third plurality; and
c) for each message element, determine a branch modulation quality inversely related to a combination of the I branch deviation and the Q branch deviation.
18. The wireless receiver of claim 17 , further configured to:
a) for each message element, using the processor, determine a first signal-to-noise ratio of the sum-signal, a second signal-to-noise ratio of the I branch signal, and a third signal-to-noise ratio of the Q branch signal.
19. The wireless receiver of claim 18 , further configured to:
a) for each message element, using the processor, determine an overall modulation quality comprising a combination of the sum-signal modulation quality, the branch modulation quality, and the first, second, and third signal-to-noise ratios.
20. The wireless receiver of claim 19 , further configured to:
a) select, using the processor, a particular message element having a lowest overall modulation quality;
b) in a nested grid search, successively replace the particular message element with a substitute message element, wherein the substitute message element comprises one of the predetermined sum-signal amplitude levels multiplexed with one of the predetermined sum-signal phase levels, wherein the nested grid search comprises all combinations of the predetermined sum-signal amplitude levels and the predetermined sum-signal phase levels; and
c) for each of the substitutions, determine whether the message, including the substituted message element, is corrupted.