Patent ID: 7711061

Claim:
A method for generating a preamble of a data frame for a multiple input multiple output (MIMO) wireless communication, the method comprising: determining at least one system condition preamble format parameter, the at least one system condition preamble format parameter including a channel signal to noise ratio (SNR) between a transmitting MIMO wireless device and a receiving MIMO wireless device; and based upon the preamble format parameter, selecting one of a plurality of preamble formats, each preamble format including a respective format of a high throughput signal field, the selecting including: for a first system condition preamble format parameter, using a first preamble format, the high throughput signal field of the first preamble format including one QPSK OFDM symbol; for a second system condition preamble format parameter, using a second preamble format that differs from the first preamble format, the high throughput signal field of the second preamble format including two BPSK OFDM symbols that are both rotated by 90 degrees; and for a third system condition preamble format parameter, using a third preamble format that differs from both the first preamble format and the second preamble format, the high throughput signal field of the third preamble format including two BPSK OFDM symbols, one of which is rotated by 90 degrees; the selecting further including: when a relatively higher channel SNR exists, using a relatively higher order modulation for the high throughput signal field; and when a relatively lower channel SNR exists, using a relatively lower order modulation for the high throughput signal field.