Method and apparatus for improved short preamble formats in a multiple antenna communication system

A multiple antenna communication system, comprising:

• N transmit antennas for transmitting a short preamble format having a legacy portion and a high throughput portion, wherein said legacy portion comprises a legacy long training field and said high throughput portion comprises N−1 high throughput long training fields, wherein a transmission of at least a portion of said short preamble on a first of said N antennas is delayed relative to a transmission of said at least said portion of said short preamble on a second of said N antennas, wherein said delay is a non-orthogonal amount to introduce variation across said preambles transmitted on said N transmit antennas.

A method for receiving data in a multiple antenna communication system having N receive antennas, said method comprising the step of:

• receiving on each of said N receive antennas a short preamble format having a legacy portion and a high throughput portion, wherein said legacy portion comprises a legacy long training field and said high throughput portion comprises N−1 high throughput long training fields, wherein at least a portion of said short preamble received on a first of said N antennas is delayed relative to a said at least said portion of said short preamble received on a second of said N antennas, wherein said delay is a non-orthogonal amount to introduce variation across said preambles transmitted on said N transmit antennas.

X multiple antenna communication system, comprising:

• N receive antennas for receiving a short preamble format having a legacy portion and a high throughput portion, wherein said legacy portion comprises a legacy long training field and said high throughput portion comprises N−1 high throughput long training fields, wherein at least a portion of said short preamble received on a first of said N antennas is delayed relative to said at least said portion of said short preamble received on a second of said N antennas, wherein said delay is a non-orthogonal amount to introduce variation across said preambles transmitted on said N transmit antennas.