US 9,813,112 B2  
Power control method, device, and system  
Jie Lv, Wuhan (CN); and Xiang Wang, Shenzhen (CN)  
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)  
Filed by Huawei Technologies Co., Ltd., Shenzhen, Guangdong (CN)  
Filed on Oct. 30, 2015, as Appl. No. 14/928,567.  
Application 14/928,567 is a continuation of application No. PCT/CN2013/075148, filed on May 3, 2013.  
Prior Publication US 2016/0049990 A1, Feb. 18, 2016  
Int. Cl. H04B 3/487 (2015.01); H04L 5/00 (2006.01); H04B 3/32 (2006.01); H04L 27/26 (2006.01) 
CPC H04B 3/487 (2015.01) [H04B 3/32 (2013.01); H04L 5/0042 (2013.01); H04L 5/0085 (2013.01); H04L 27/2601 (2013.01)]  13 Claims 
1. A power control method for use in a vectoring system, wherein the vectoring system comprises multiple lines, each line
comprises multiple subcarriers, and for each subcarrier, a crosstalk channel is formed between the multiple lines, the method
comprising:
obtaining a closed subcarrier set of the multiple lines according to line crosstalk channel information corresponding to each
subcarrier of the multiple subcarriers, wherein the closed subcarrier set comprises a subcarrier set required to be closed
on the multiple lines;
sending the closed subcarrier set of the multiple lines to a transceiver;
wherein obtaining the closed subcarrier set of the multiple lines comprises:
calculating, according to the line crosstalk channel information corresponding to each subcarrier, a line set required to
be closed and corresponding to each subcarrier, and
searching, according to the calculated line set corresponding to each subcarrier, for a subcarrier required to be closed on
each line in the line set, to obtain the subcarrier set, required to be closed, of the multiple lines;
wherein calculating the line set required to be closed and corresponding to each subcarrier comprises:
estimating a power gain factor according to the line crosstalk channel information corresponding to each subcarrier, and adding
a line that makes the estimated power gain factor greater than a threshold to the line set required to be closed and corresponding
to each subcarrier;
wherein the line crosstalk channel information corresponding to each subcarrier comprises a channel matrix corresponding to
each subcarrier; and
wherein estimating the power gain factor according to the line crosstalk channel information corresponding to each subcarrier,
and adding a line that makes the estimated power gain factor greater than a threshold to the line set required to be closed
and corresponding to each subcarrier comprises:
calculating, according to a channel matrix corresponding to any subcarrier, a cancellation matrix P^{k }of the any subcarrier, and using each element in P^{k }as an estimated power gain factor,
determining whether each element in P^{k }of the any subcarrier is greater than a first preset threshold, and
when an element P^{k}_{ij }in P^{k }of the any subcarrier is greater than the first preset threshold, adding a line with a lower priority of a line i and a line
j to a line set required to be closed and corresponding to the any subcarrier, wherein P^{k}_{ij }denotes a cancellation coefficient of crosstalk of the line j to the line i.
