| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for efficient group definition and overloading for downlink multiuser multiple-input multiple-output (MU-MIMO) transmissions in wireless communications.SOLUTION: A preamble 400 comprises an omni-legacy portion 402 and a precoded 802.11ac VHT (Very High Throughput) portion 404. The legacy portion 402 comprises at least one of a Legacy Short Training Field (L-STF) 406, a Legacy Long Training Field (L-LTF) 408, a Legacy Signal (L-SIG) 410, and two OFDM symbols 412, 414 for VHT Signal type A (VHT-SIGA) fields 412. The VHT-SIGA fields 412, 414 are transmitted omni-directionally, and indicate allocation of many spatial streams to a combination of a plurality of STAs. |
