High efficiency long training field symbol transmission for multiple transmission streams
摘要
說明書
The HE-LTF symbols are transmitted, in some implementations, over a plurality of wireless spatial streams and the control circuitry is further configured to assign a subset of the wireless spatial streams to a set of tones in the wireless channel. In some embodiments, the control circuitry is further configured to cyclically shift the rows of the LTF mapping matrix a predetermined number of times such that each tone of the set of tones is associated with a cyclically shifted LTF mapping matrix by shifting the rows of a predetermined LTF mapping matrix cyclically by a number corresponding to a modulo of a tone number over which the shifted LTF mapping matrix is transmitted.
Embodiments described herein further provide a system for channel estimation based on High Efficiency Long Training Field (HE-LTF) symbols transmitted to a receiver over a wireless channel by a transmitter over a plurality of tones. Control circuitry, coupled to the transmitter, is configured to assign, based on a modulo operation applied to tone indices corresponding to the plurality of tones, a plurality of wireless spatial streams to the plurality of tones. In some embodiments, a subset of the plurality of tones is separated by one or more tones unassigned to the subset of the plurality of tones. The control circuitry is further configured to generate, based on the assigned plurality of wireless spatial streams, the HE-LTF symbols for estimating, at the receiver, the wireless channel having bandwidth coherency within the plurality of tones. The transmitter configured to transmit, over the plurality of tones, the generated HE-LTF symbols for interpolation of a channel estimate matrix corresponding to the one or more tones unassigned to the subset of the unassigned tones.
