FIELD: radio engineering, communication.
SUBSTANCE: invention relates to communication engineering and can be used in wireless systems for phase tracking using pilot signals. In a multiple-input, multiple-output (MIMO) system, demodulation of the receiving circuit of a wireless node is enhanced to include phase tracking. Instead of performing phase tracking over data symbols, VHT long training fields (LTF) embedded in a frame preamble are used for phase tracking. Single stream pilot signals are added during transmission of VHT-LTF. This enables the receiving side to estimate the channel using the pilot signals in a first set of LTF. A second set of LTF is then used to estimate the phase of pilot signals using the estimated channel.
EFFECT: phase estimate obtained in this manner is continuously applied to other received data tone signals across the VHT-LTF data symbols; phase errors due to PLL mismatches and phase noise are reduced at reception, leading to better signal to noise ratio for different levels of parts per million of drift and frequency offset; MIMO channel estimation is more accurate, improving the overall wireless network when the accurate MIMO channel estimation data are used in calibration and handshake between wireless nodes.
31 cl, 8 dwg
