Optimized QAM transmission
Systems and methods to optimize QAM transmission are provided. In some implementations, a QAM transmitter can operate to optimize QAM transmissions by reducing high peak signals levels via a QAM subgroup inversion. In additional implementations, systems and methods can provide for a QAM transmitter to optimize QAM transmissions by applying a recursive inversion process of QAM blocks to minimize peak output. In still further implementations, systems and methods can provide for a QAM transmitter to optimize QAM transmissions by suppressing QAM subgroups in a circular QAM constellation. Optimizing QAM transmission can provide enhancement in power efficiency of active transmission equipment thereby avoiding high peak signal levels and reducing the instances of clipping.
1. An optimized quadrature amplitude modulation (QAM) transmission system comprising:
an interface operable to transmit QAM symbol data;
a transmission module operable to predict a peak power value expected for transmission of a given set of QAM symbol data; and
the transmission module further operable to dynamically adjust a subgroup of QAM symbol data based on the predicted peak power value to reduce peak power value used to transmit QAM symbol data below a threshold;
wherein the transmission module is operable to dynamically adjust QAM symbol data to reduce the predicted peak power value by delaying QAM symbol data transmission by storing QAM symbol data in a data buffer, a depth of the data buffer being managed by prioritizing transmissions of input data that has been buffered.
2. The optimized QAM transmission system of claim 1 wherein the adjustment of QAM symbol data includes at least a suppression of QAM symbols.
3. The optimized QAM transmission system of claim 2 wherein the adjustment of QAM symbol data is a delay of QAM symbol data transmission.
4. The optimized QAM transmission system of claim 3 wherein the delay is accomplished by storing QAM symbol data in a data buffer.
5. The optimized QAM transmission system of claim 1 wherein the adjustment of QAM symbol data includes at least an inversion of QAM symbol data.
6. The optimized QAM transmission system of claim 5 wherein the inversion of QAM symbol data is performed recursively.
7. The optimized QAM transmission system of claim 1 wherein the adjustment of QAM symbol data is an inversion of QAM signal sign.
8. The optimized QAM transmission system of claim 7 wherein the inversion of QAM symbol data is performed recursively.
9. The optimized QAM transmission system of claim 1 wherein the adjustment is based on a choice between equivalent transmitted data patterns to represent QAM symbol data wherein patterns are chosen to result in a reduced peak power value.
10. A method for optimizing quadrature amplitude modulation (QAM) transmission, comprising:
predicting a peak power value resulting from a given set of QAM symbol data;
adjusting a subgroup of the QAM symbol data based on the predicted peak power value to reduce peak power value used to transmit QAM symbol data; and
transmitting QAM symbol data via the QAM transmitter;
receiving QAM symbol data via a QAM receiver;
detecting an adjustment to the subgroup QAM symbol data; and
recovering the original QAM symbol data;
wherein adjusting QAM symbol data performs an inversion of a subgroup of QAM symbol data, the inversion of the subgroup of QAM symbol data being performed recursively within the subgroup of QAM symbol data.
11. The method of claim 10 wherein adjusting QAM symbol data is based on a choice between equivalent transmitted data patterns to represent QAM symbol data wherein patterns are chosen with a reduced peak power value.
12. The method of claim 10 wherein adjusting QAM symbol data results in a delay of QAM symbol data transmission.
13. The method of claim 12 wherein the delay is accomplished by storing QAM symbol data in a data buffer, a depth of the data buffer being managed by prioritizing transmission of input data that has been buffered.
14. A method for optimizing quadrature amplitude modulation (QAM) transmissions, comprising:
predicting a peak power value resulting from a given set of QAM symbol data;
adjusting a subgroup of the QAM symbol data based on the predicted peak power value to reduce peak power value used to transmit QAM symbol data;
transmitting QAM symbol data via the QAM transmitter;
receiving QAM symbol data via a QAM receiver;
detecting an adjustment to the subgroup QAM symbol data; and
recovering the original QAM symbol data;
wherein adjusting QAM symbol data results in a delay of QAM symbol data transmission, and the delay is accomplished by storing QAM symbol data in a data buffer, the data buffer depth being managed by prioritizing transmission of input data that has been buffered.
15. A method for optimizing quadrature amplitude modulation (QAM) transmission, comprising:
predicting a peak power value resulting from a given set of QAM symbol data;
dynamically suppressing a subgroup of QAM symbol data based on the predicted power value to reduce peak power value used to transmit QAM symbol data; and
transmitting QAM symbol data via the QAM transmitter;
receiving QAM symbol data via a QAM receiver; and
detecting a suppressed subgroup of QAM symbol data;
wherein dynamically suppressing QAM symbol data results in a delay of QAM symbol data transmission by storing by storing QAM symbol data in a data buffer, a depth of the data buffer being managed by prioritizing transmission of input data that has been buffered.
16. The method of claim 15 wherein the QAM symbol data constellation is a circular QAM constellation.
17. The method of claim 16 wherein the circular QAM constellation contains one or more extra constellation states used to indicate the suppressed subgroup of QAM symbol data.
18. The method of claim 15 wherein the combined QAM signals constitute an OFDM signal.