Patent ID: 8611439

Claim:
In a multicarrier communication system including a transmitter and a receiver, a method for allocating power to a plurality of subcarriers of a communication channel between the transmitter and the receiver at a required bit error rate, the method comprising the steps of: a. transmitting said plurality of subcarriers with an initial set of power levels and an initial set of constellation assignments; b. measuring at the receiver a quantized Signal to Noise Ratio (SNR) metric value for each subcarrier; c. for each subcarrier, comparing the measured subcarrier quantized SNR metric value with a quantized SNR metric corresponding to the respective currently allocated constellation, for determining an excess SNR per subcarrier; and d. adjusting the transmitter power of the subcarriers whose excess SNR is above a predetermined threshold while keeping the total transmitter power constant, wherein adjusting the transmitter power comprises increasing the excess quantized SNR metric of selected subcarriers whose excess SNR is above the predetermined threshold for allowing said selected subcarriers to be allocated to respective denser constellations than their respective currently allocated constellations, wherein adjusting the transmitter power of the subcarriers whose excess SNR is above predetermined threshold comprises allocating more power to subcarriers with excess SNR above a subthreshold higher than said predetermined threshold and decreasing the power of complementary set.