Patent ID: 8867462

Claim:
A method of allocating a long training field for transmitting in a multi-user multiple input multiple output based radio communication system, the method comprising: determining, for a first and a second station each having one or more data transmissions streams, a first quantity of data transmission streams for the first station transmitted by a first subcarrier and a second quantity of data transmission streams for the second station transmitted by a second subcarrier; calculating a first number of long training fields for the first station corresponding to the first quantity of data transmission streams and a second number of long training fields for the second station corresponding to the second quantity of data transmission streams; calculating a least common multiple of long training fields for each of the first and second station; comparing the least common multiple of the long training fields of the first and second station and selecting the largest least common multiple; and allocating in the first and second subcarrier a number of symbols corresponding to the largest least common multiple, wherein the long training fields for a first or second subcarrier are repeatedly allocated to the number of symbols corresponding to the largest least common multiple when the least common multiple of the first or second subcarrier is less than the largest least common multiple of long training fields, and wherein the long training fields for a subcarrier are allocated to the number of symbols corresponding to the largest least common multiple when the least common multiple of the subcarrier is the same as the largest least common multiple of long training fields.