Method and system for compromise greenfield preambles for 802.11n

摘要

Aspects of the invention described herein may enable a greenfield access mode in IEEE 802.11n WLAN systems in comparison to an alternative approach that may not provide greenfield access. The utilization of greenfield access may reduce the portion of time required to transmit data due to overhead comprising preamble fields and header fields. This may enable higher data throughput rates to be achieved. This may further enable more robust transmission of data by enabling comparable data rates to be maintained while reducing the coding rate of encoded transmitted data. The reduction of the coding rate may enable comparable data rates to be maintained for transmission via RF channels characterized by lower SNR while still achieving desired target levels of packet error rates. In another aspect of the invention, mixed mode access may be achieved while reducing the portion of time required for transmitting data due to overhead.

主权项

1. A communication device comprising:
at least one communication interface to receive a signal adapted for Greenfield access via a plurality of antennas, wherein:
the signal including, for a first spatial stream, a first HT (high throughput) short training field (STF) followed by a first single HT long training field (LTF) followed by a first signal (SIG) field followed by a first plurality of HT LTFs followed by a first data field, wherein the first plurality of HT LTFs have the same collective duration as the first single HT LTF;the signal also including, for a second spatial stream, a second HT-STF, a second single HT LTF, a second SIG field, and a second plurality of HT LTFs wherein the second plurality of HT LTFs have the same collective duration as the second single HT LTF; andthe first plurality of HT LTFs having a corresponding plurality of single symbols and the second plurality of HT LTFs having a corresponding plurality of single symbols; and wherein: the second HT-STF being a cyclic diversity delay shifted version of the first HT-STF; the second single HT LTF being a cyclic diversity delay shifted version of the first single HT LTF; the second SIG field being a cyclic diversity delay shifted version of the first SIG field; and at least one of the second plurality of HT LTFs being a cyclic diversity delay shifted version of at least one of the first plurality of HT LTFs; and wherein the at least one communication interface includes low noise amplification circuitry and wherein the at least one communication interface extracts and uses at least one of: the first HT-STF or the second HT-STF, for automatic gain control (AGC) of the low noise amplification circuitry.