Identifying specific faults in 5G/6G messages by modulation quality
Faulted messages in 5G or 6G are generally discarded and a retransmission is then requested. However, the faulted message contains valuable information despite the few faulted message elements. Retransmission is a time-consuming energy-intensive process. Therefore, the present disclosure pertains to procedures for determining which specific message elements, of a corrupted message, are actually faulted. To do so, the receiver can determine a modulation quality of each message element by measuring a difference between the amplitude levels of the message element and the predetermined amplitude levels of the modulation scheme. For example, the modulation scheme may involve an I-branch and an orthogonal Q-branch, each with a different amplitude. The message quality may be related to the deviation of each branch amplitude from the closest predetermined amplitude level of the modulation scheme. A large amplitude deviation indicates a suspicious message element. Many other aspects are also disclosed.
1. Non-transitory computer-readable media in a wireless receiver, the media comprising instructions that when executed in a computing environment cause a method to be performed, the method comprising:
a. receiving a wireless message, the message comprising modulated message elements, each message element modulated according to a modulation scheme, the modulation scheme comprising an I-branch signal combined with a Q-branch signal, the Q-branch signal being offset in phase relative to the I-branch signal, each I-branch and Q-branch signal amplitude modulated according to one respective amplitude level of a plurality of predetermined amplitude levels;
b. determining that the message disagrees with an error-detection code associated with the message; and
c. determining, for each message element, a modulation quality according to an I-branch difference and a Q-branch difference, the I-branch difference comprising a difference between a measured I-branch amplitude value and a closest one of the predetermined amplitude levels, and the Q-branch difference comprising a difference between a measured Q-branch amplitude value and a closest one of the predetermined amplitude values.
2. The media of claim 1 , wherein the message conforms to 5G or 6G technology.
3. The media of claim 1 , wherein the modulation quality is inversely related to the I-branch difference and to the Q-branch difference, whereby a message element having a larger I-branch difference and a larger Q-branch difference has a lower modulation quality, and a message element having a smaller I-branch difference and a smaller Q-branch difference has a higher modulation quality.
4. The media of claim 1 , wherein the determining, for each message element, a modulation quality comprises calculating an inverse of a square root of a sum of the I-branch difference squared plus the Q-branch difference squared.
5. The media of claim 1 , wherein the determining, for each message element, a modulation quality comprises adding a magnitude of the I-branch difference to a magnitude of the Q-branch difference.
6. The media of claim 1 , wherein the determining, for each message element, a modulation quality comprises:
a. measuring a signal-to-noise ratio of the message element; and
b. combining the signal-to-noise ratio with the I-branch difference and the Q-branch difference according to a formula.
7. The media of claim 1 , the method further comprising:
a. determining which particular message element has a lowest modulation quality; and
b. in a nested search, sequentially replacing the I-branch amplitude of the particular message element with each of the predetermined levels, and replacing the Q-branch amplitude with each of the predetermined levels, and determining whether the message so altered agrees with the error-detection code.
8. The media of claim 1 , the method further comprising:
a. determining, for each message element, a sum-signal comprising the I-branch signal plus the Q-branch signal;
b. measuring an amplitude of the sum-signal; and a phase of the sum-signal
c. calculating a sum-signal amplitude difference comprising a difference between the amplitude of the sum-signal and a predetermined sum-signal amplitude level of the modulation scheme;
d. calculating a sum-signal phase difference comprising a difference between the phase of the sum-signal and a predetermined sum-signal phase level of the modulation scheme;
e. determining that the message element is faulted if a magnitude of the sum-signal amplitude difference exceeds a first predetermined threshold or if a magnitude of the sum-signal phase difference exceeds a second predetermined threshold.
9. A method for a wireless receiver to mitigate a faulted message, the method comprising:
a. receiving or determining a threshold;
b. receiving a message comprising message elements, each message element modulated according to a modulation scheme comprising a plurality of predetermined amplitude levels;
c. determining, for each message element, an I-branch signal and an orthogonal Q-branch signal;
d. calculating a first difference comprising an amplitude of the I-branch signal minus a first predetermined amplitude level, and calculating a second difference comprising an amplitude of the Q-branch signal minus a second predetermined amplitude level; and
e. determining whether the message element is faulted by comparing a magnitude of the first difference or a magnitude of the second difference to the threshold.
10. The method of claim 9 , further comprising:
a. counting a number of faulted message elements in the message; and
b. if the number of faulted message elements exceeds a predetermined limit, requesting a retransmission of the message.
11. The method of claim 10 , further comprising:
a. if the number of faulted message elements is less than the predetermined limit, determining which particular message element has a largest difference, of the first and second differences;
b. sequentially altering the amplitude of the I-branch signal of the particular message element to each of the predetermined levels, and sequentially altering the amplitude of the Q-branch signal of the particular message element to each of the predetermined levels, in a nested search; and
c. for each alteration, determining whether the message, including the particular message element so altered, agrees with an error-detection code.
12. The method of claim 9 , further comprising:
a. determining whether the message agrees with an associated error-detection code;
b. if the message disagrees with the error-detection code and includes zero message elements with modulation quality below the threshold, raising the threshold; and
c. if the message agrees with the error-detection code and includes at least one message element with modulation quality below the threshold, lowering the threshold.
13. The method of claim 9 , further comprising:
a. for each message element, calculating or measuring a signal-to-noise ratio associated with the message element;
b. determining a modulation quality by combining the first difference, the second difference, and the signal-to-noise ratio according to a formula; and
c. determining that the message element is faulted by comparing the modulation quality to the threshold.
14. The method of claim 13 , further comprising:
a. determining a sum-signal by adding the I-branch signal to the Q-branch signal;
b. determining a sum-signal amplitude and a sum-signal phase according to the sum-signal;
c. determining one or more sum-signal amplitude levels of the modulation scheme, and determining one or more sum-signal phase levels of the modulation scheme;
d. determining a third difference comprising the sum-signal amplitude minus a closest predetermined sum-signal amplitude level of the modulation scheme, and determining a fourth difference comprising the sum-signal phase minus a closest predetermined sum-signal phase level of the modulation scheme; and
e. determining a modulation quality according to the first, second, third, and fourth differences.
15. A wireless receiver comprising a processor, the processor configured to:
a. receive a message and an error-detection code associated with the message, the message comprising one or more message elements, each message element comprising a first signal plus a second signal orthogonal to the first signal, each of the first and second signals modulated according to one or more predetermined amplitude levels of a modulation scheme;
b. determine, for each message element, a first amplitude value of the first signal and a second amplitude value of the second signal;
c. determine, for each message element, a modulation quality related to a first difference between the first amplitude value and a closest one of the predetermined amplitude levels of the modulation scheme, and further related to a second difference between the second amplitude value and a closest one of the predetermined amplitude levels of the modulation scheme;
d. if a hash or digest of the message disagrees with the error-detection code, select a message element having lower modulation quality than any other message element in the message;
e. alter the first amplitude value and the second amplitude value of the selected message element successively to each of the predetermined amplitude levels of the modulation scheme in a nested search; and
f. for each alteration, determine whether the message, including the selected message element so altered, agrees with the error-detection code.
16. The wireless receiver of claim 15 , wherein the determine a modulation quality comprises for each message element, determine a first magnitude of the first difference and a second magnitude of the second difference, wherein the modulation quality is related to the larger of the first and second magnitudes.
17. The wireless receiver of claim 15 , wherein the determine a modulation quality comprises for each message element, determine a sum by adding a first magnitude of the first difference plus a second magnitude of the second difference, wherein the modulation quality is related to the sum.
18. The wireless receiver of claim 15 , wherein the determine a modulation quality comprises for each message element, determine a first square of the first difference and a second square of the second difference, wherein the modulation quality is related to a square root of a sum of the first and second squares.
19. The wireless receiver of claim 15 , wherein the determine a modulation quality comprises:
a. for each message element, determine a signal-to-noise ratio of the message element; and
b. calculate the modulation quality according to a mathematical combination of the first difference, the second difference, and the signal-to-noise ratio of the message element.
20. The wireless receiver of claim 15 , wherein the determine a modulation quality comprises:
a. for each message element, determine a sum-signal by adding the first signal to the orthogonal second signal;
b. determine a sub-signal amplitude of the sum-signal and a sum-signal phase of the sum-signal;
c. determine one or more predetermined sum-signal amplitude levels of the modulation scheme and one or more predetermined sum-signal phase levels of the modulation scheme;
d. determine a third difference between the sum-signal amplitude and a closest predetermined sum-signal amplitude level of the modulation scheme, and determine a fourth difference between the sum-signal phase and a closest predetermined sum-signal phase level of the modulation scheme; and
e. determine the modulation quality according to a formula that takes, as input, the first, second, third, and fourth differences and produces, as output, a determination of the modulation quality.