Adaptive aggregation of metrics for OFDM/OFDMA profile generation
Devices, systems and methods for adaptively associating a percentile value to each of a plurality of subcarriers at which a cable modem communicates data, the percentiles value used to respectively determine an aggregated RxMER value for each subcarrier. The aggregated RxMER values for the subcarriers may be used to determine and assign one or more bitloading profiles to the cable modem.
1 . A method for allocating bitloading profiles to a cable modem, the method comprising:
receiving error data for the cable modem spanning a plurality of subcarriers;
selecting a range of subcarriers;
determining a percentile value based on an analysis of the error data in the selected range;
using the percentile value to determine an aggregated error metric;
associating the aggregated error metric with each subcarrier in the selected range;
determining a plurality of bitloading profiles based on the association of the aggregated error metric with each subcarrier in the selected range; and
allocating at least one of the plurality of bitloading profiles to the cable modems in a manner that affects the throughput of at least one of an OFDM transmission to the cable modem and OFDMA transmission from the cable modem.
2 . The method of claim 1 where the selected range of subcarriers includes less than the number of subcarriers in the plurality of subcarriers.
3 . The method of claim 1 where the selected range of subcarriers is a single subcarrier.
4 . A method for allocating bitloading profiles to a cable modem, the method comprising:
receiving error data for the cable modem spanning a plurality of subcarriers, each subcarrier having a plurality of error datum associated with it;
incrementally selecting each subcarrier in the plurality of subcarriers and, for each incrementally selected subcarrier:
determining a percentile value based upon an analysis of the respectively associated plurality of error datum; and
using the determined percentile value to associate an aggregated error metric for the selected subcarrier;
determining a plurality of bitloading profiles based on the association of the aggregated error metric for each subcarrier in the plurality of subcarriers; and
allocating at least one of the plurality of bitloading profiles to the cable modems in a manner that affects the throughput of at least one of an OFDM transmission to the cable modem and OFDMA transmission from the cable modem.
5 . The method of claim 4 where the percentile value varies over the plurality of subcarriers.
6 . The method of claim 4 where lower percentile values are associated with subcarrier frequencies whose error value distributions have negative skews.
7 . The method of claim 6 including using a measurement of skew to determine the percentile value.
8 . The method of claim 4 where lower percentile values are associated with subcarriers having a higher probability of mobile interference in a subcarrier.
9 . The method of claim 8 including estimating a probability of mobile interference in a subcarrier from the error data.
10 . A CMTS having a processor configured to:
receive error data for a cable modem spanning a plurality of subcarriers, each subcarrier having a plurality of error datum associated with it;
incrementally select each subcarrier in the plurality of subcarriers and, for each incrementally selected subcarrier:
determine a percentile value based upon an analysis of the respectively associated plurality of error datum; and
use the determined percentile value to associate an aggregated error metric for the selected subcarrier;
determine a plurality of bitloading profiles based on the association of the aggregated error metric for each subcarrier in the plurality of subcarriers; and
allocate at least one of the plurality of bitloading profiles to the cable modems in a manner that affects the throughput of at least one of an OFDM transmission to the cable modem and OFDMA transmission from the cable modem.
11 . The CMTS of claim 10 where the percentile value varies over the plurality of subcarriers.
12 . The CMTS of claim 10 where lower percentile values are associated with subcarrier frequencies whose error value distributions have negative skews.
13 . The CMTS of claim 12 including using a measurement of skew to determine the percentile value.
14 . The CMTS of claim 10 where lower percentile values are associated with subcarriers having a higher probability of mobile interference in a subcarrier.
15 . The CMTS of claim 14 including estimating a probability of mobile interference in a subcarrier from the error data.