| abstract |
Apparatus and method for transmitting symbols according to one frame structure in a multi-antenna communication system are disclosed, wherein the symbols are interpreted by a lower order receiver (ie, a receiver having fewer antennas than the transmitter). Can be. The disclosed frame structure includes a legacy preamble with at least one long training symbol and N-1 additional long training symbols transmitted on each of the N transmit antennas. The legacy preamble may be, for example, an 802.11 a / g preamble including at least one short training symbol, at least one long training symbol, and at least one signal field.n n n Each series of long training symbols on the N transmit antennas is orthogonal in the time domain. The long training symbols may be orthogonal in the time domain by inducing a phase shift with respect to each of the long training symbols. |