초록 ▼

An adaptive multicarrier wireless communication system, apparatus and associated methods are generally disclosed herein. In at least one embodiment, channel state information is used to perform bit loading and power allocation within a multicarrier system. In an example technique, after active subca

An adaptive multicarrier wireless communication system, apparatus and associated methods are generally disclosed herein. In at least one embodiment, channel state information is used to perform bit loading and power allocation within a multicarrier system. In an example technique, after active subcarriers have been identified for a multicarrier channel and an initial power distribution has been made, a subset of active subcarriers may be found that exceed a channel quality performance threshold. Excess power may then be identified by determining how much power could be reduced in the identified subcarriers so that they still meet, but do not exceed the channel quality performance threshold. In one possible approach, the excess power may be re-allocated to other subcarrier subsets.

대표청구항 ▼

What is claimed is: 1. A method comprising: receiving channel state information associated with a multicarrier wireless communication channel having a plurality of subcarriers, wherein the channel is processed to identify active subcarriers and initial power distribution among the subcarriers; and

What is claimed is: 1. A method comprising: receiving channel state information associated with a multicarrier wireless communication channel having a plurality of subcarriers, wherein the channel is processed to identify active subcarriers and initial power distribution among the subcarriers; and selecting a bit loading and final power distribution for use in subsequent processing of the subcarriers of the communication channel based, at least in part, on the received channel state information, wherein the bit loading and final power distribution increases channel throughput while guaranteeing a channel quality metric among active subcarriers; wherein selecting a bit loading and final power distribution includes: identifying among the active subcarriers, those which exceed a channel quality performance threshold, said identified subcarriers forming a highest rate subset of subcarriers; calculating an excess power value by determining how much power could be reduced in the identified subcarriers, from the initial power distribution, so that they still meet, but do not exceed, the channel quality performance threshold; and reallocating at least a portion of the excess power from the highest-rate subset of subcarriers to one or more lower-rate subsets of subcarriers. 2. A method according to claim 1, wherein identification of active subcarriers and power distribution in the multicarrier wireless communication channel was initially established using a water-filling technique. 3. A method according to claim 2, the water-filling technique comprising: sorting the subcarriers according to a channel performance metric; identifying as a threshold among the sorted subcarriers a subcarrier that fails to meet the channel performance metric, wherein the subcarriers above or below the threshold are identified as bad subcarriers; deactivating the bad subcarriers; and distributing the available power among active subcarriers of the communication channel. 4. A method according to claim 3, wherein the channel state information is received from a remote device. 5. A method according to claim 4, the channel state information comprising one or more channel processing parameters including bit loading, coding type, modulation type and power allocation, determined by the remote device. 6. A method according to claim 4, wherein the channel state information is representative of one or more of channel performance characteristics and channel quality characteristics. 7. A method according to claim 6, wherein the channel performance characteristics include radio frequency (RF) characteristics comprising one or more of a received signal strength indication (RSSI), a signal to noise ratio (SNR), a signal to interference and noise ratio (SINR), fading characteristic(s), and Doppler characteristics. 8. A method according to claim 6, wherein the channel quality characteristics include one or more of a bit-error rate (BER), a packet-error rate (PER), a symbol-error rate (SER), and a frame error rate (FER). 9. A method according to claim 1, wherein reallocating comprises applying the excess power to deactivated subcarriers in lower-rate subsets to increase a number of active subcarriers and channel throughput. 10. A method according to claim 1, further comprising: modifying at least a subset of initial power coefficients to reactivate one or more subcarriers which were initially deactivated. 11. A method according to claim 3, wherein the channel state information is received from a local receiver and is representative of an estimate of a channel transfer function. 12. A method according to claim 11, wherein the channel transfer function is one or more of channel transfer function estimate in the frequency domain and a channel transfer function estimate in the time domain based on receipt of a wireless signal transmitted from a remote device. 13. A method according to claim 1, the element of selecting a bit loading and final power distribution comprising: after reallocating: second identifying among the active subcarriers, those which exceed a second channel quality performance threshold but which are not within said highest rate subset of subcarriers, said second identified subcarriers forming a next highest rate subset of subcarriers; second calculating an excess power value by determining how much power could be reduced in the second identified subcarriers so that they still meet, but do not exceed, the second channel quality performance threshold; and updating the original excess power value based on the excess power associated with the second identified subcarriers. 14. A method according to claim 13, further comprising: after updating: third identifying among the active subcarriers, those which exceed a third channel quality performance threshold but which are not within said highest or next highest rate subset of subcarriers, said third identified subcarriers forming a third highest rate subset of subcarriers; third calculating an excess power value by determining how much power could be reduced in the third identified subcarriers so that they still meet, but do not exceed, the third channel quality performance threshold; and second updating the original excess power value based on the excess power associated with the third identified subcarriers. 15. A method according to claim 1, further comprising: issuing a message to a remote transmitter to apply the bit loading and final power distribution to subsequent processing of the multicarrier communication channel. 16. A computer readable storage medium comprising content which, when executed by an accessing device, causes the device to implement a method according to claim 1. 17. An apparatus comprising: a transceiver, to establish a multicarrier communication channel with a remote transceiver; and a subcarrier management agent (SMA), coupled with the transceiver, to receive channel state information associated with a multicarrier wireless communication channel having a plurality of subcarriers, wherein the channel is processed to identify active subcarriers and initial power distribution among the subcarriers, and to select a bit loading and final power distribution for use in subsequent processing of the subcarriers of the communication channel based, at least in part, on the received channel state information, wherein the bit loading and final power distribution increases channel throughput while guaranteeing a channel quality metric among active subcarriers; wherein the SMA identifies, among the active subcarriers, those which exceed a channel quality performance threshold, calculates how much power could be reduced in the identified subcarriers, from the initial power distribution, so that they still meet, but do not exceed, the channel quality performance threshold to identify an excess power level, and reallocates at least a portion of the excess power from a higher-rate subset of subcarriers to one or more lower-rate subsets of subcarriers. 18. An apparatus according to claim 17, wherein the SMA employs a water-filling technique to identify active subcarriers and initial power distribution in the multicarrier wireless communication channel. 19. An apparatus according to claim 18, wherein the SMA sorts the subcarriers according to a channel performance metric, identifies as a threshold among the sorted subcarriers a subcarrier that fails to meet the channel performance metric, wherein the subcarriers above or below the threshold are identified as bad subcarriers, deactivates the identified bad subcarriers, and distributes the available power among active subcarriers of the communication channel. 20. An apparatus according to claim 19, the channel state information comprising one or more channel processing parameters including bit loading, coding type, modulation type and power allocation, determined by the remote device. 21. An apparatus according to claim 19, wherein the channel state information is representative of one or more of channel performance characteristics and channel quality characteristics. 22. An apparatus according to claim 21, wherein the channel performance characteristics include radio frequency (RF) characteristics comprising one or more of a received signal strength indication (RSSI), a signal to noise ratio (SNR), a signal to interference and noise ratio (SINR), fading characteristic(s), and Doppler characteristics. 23. An apparatus according to claim 21, wherein the channel quality characteristics include one or more of a bit-error rate (BER), a packet-error rate (PER), a symbol-error rate (SER), and a frame error rate (FER). 24. An apparatus according to claim 17, wherein the SMA selectively reallocates at least a portion of the excess power value identified in one or more higher-rate subsets to deactivated subcarriers in lower-rate subsets to increase a number of active subcarriers, and channel throughput. 25. An apparatus according to claim 24, wherein the SMA dynamically generates updated power coefficients to replace at least a subset of initial power coefficients, and selectively applies the updated coefficients to a weighting element of the transmitter. 26. An apparatus according to claim 17, wherein the SMA dynamically generates control content comprising one or more of a bit distribution mask, a coding type, a modulation and power allocation coefficients for application to one or more elements of the transceiver. 27. A system comprising: one or more dipole antennas; a transceiver, selectively coupled to one or more of the antenna(e), to establish a multicarrier communication channel with a remote transceiver; and a subcarrier management agent (SMA), coupled with the transceiver, to receive channel state information associated with a multicarrier wireless communication channel having a plurality of subcarriers, wherein the channel is processed to identify active subcarriers and initial power distribution among the subcarriers, and to select a bit loading and final power distribution for use in subsequent processing of the subcarriers of the communication channel based, at least in part, on the received channel state information, wherein the bit loading and final power distribution increases channel throughput while guaranteeing a channel quality metric among active subcarriers; wherein the SMA identifies, among the active subcarriers, those which exceed a channel quality performance threshold, calculates how much power could be reduced in the identified subcarriers, from the initial power distribution, so that they still meet, but do not exceed, the channel quality performance threshold to identify an excess power level, and reallocates at least a portion of the excess power from a higher-rate subset of subcarriers to one or more lower-rate subsets of subcarriers. 28. A system according to claim 27, wherein the SMA employs a water-filling technique to identify active subcarriers and initial power distribution in the multicarrier wireless communication channel. 29. A system according to claim 27, the channel state information comprising one or more channel processing parameters including bit loading, coding type, modulation type and power allocation, determined by the remote device. 30. A system according to claim 27, wherein the channel state information is representative of one or more of channel performance characteristics and channel quality characteristics. 31. A system according to claim 30, wherein the channel performance characteristics include radio frequency (RF) characteristics comprising one or more of a received signal strength indication (RSSI), a signal to noise ratio (SNR), a signal to interference and noise ratio (SINR), fading characteristic(s), and Doppler characteristics. 32. A system according to claim 30, wherein the channel quality characteristics include one or more of a bit-error rate (BER), a packet-error rate (PER), a symbol-error rate (SER), and a frame error rate (FER). 33. A system according to claim 27, wherein the SMA selectively applies at least a subset of the excess power value identified in one or more higher-rate subsets to deactivated subcarriers in lower-rate subsets to increase a number of active subcarriers, and channel throughput. 34. A computer readable storage medium comprising content which, when executed by an accessing device, enables the device to selectively receive channel state information associated with a multicarrier wireless communication channel having a plurality of subcarriers, wherein the channel is processed to identify active subcarriers and initial power distribution among the subcarriers, and to select a bit loading and final power distribution for use in subsequent processing of the subcarriers of the communication channel based, at least in part, on the received channel state information, wherein the bit loading and final power distribution increases channel throughput while guaranteeing a channel quality metric among active subcarriers, wherein selection of a bit loading and final power distribution includes: operation to identify among the active subcarriers, those which exceed a channel quality performance threshold; operation to calculate an excess power value by determining how much power could be reduced in the identified subcarriers, from the initial power distribution, so that they still meet, but do not exceed, the channel quality performance threshold; and operation to reallocate at least a portion of the excess power from a higher-rate subset of subcarriers to one or more lower-rate subsets of sub carriers. 35. A storage medium according to claim 34, further comprising content which, when executed causes the accessing device to implement a water-filling technique to identify active subcarriers and initial power distribution in the multicarrier wireless communication channel. 36. A storage medium according to claim 34, wherein said operation to reallocate comprises applying the excess power to deactivated subcarriers in lower-rate subsets to increase a number of active subcarriers, and channel throughput.