MIMO slotted aloha (MSA) system

摘要

A method including receiving at a synchronizing node a first reference frame from a first reference node at a first time and storing a first time value representing the first time, and calculating a timing estimator by subtracting a minimum time value, representing the distance from the synchronizing node to the first reference node, from the first time value. The method includes receiving at the synchronizing node a second reference frame at a second time and transmitting from the synchronizing node to the first reference node a short timing contention time frame. The method includes receiving at the synchronizing node from the first reference node an arrival time value representing the time at which the first reference node received the short timing contention frame and calculating a time drift from the first arrival time value and the second time value and adjusting the timing estimator based on the time drift.

主权项

1. A method comprising:
receiving at a first node a plurality of signals from a plurality of nodes; determining a plurality of carrier frequency offsets for the plurality of nodes, wherein at least one carrier frequency offset of the plurality of carrier frequency offsets is different than another carrier frequency offset of the plurality of carrier frequency offsets; determining an average of the plurality of carrier frequency offsets; adjusting a local oscillator at the first node based on the average of the plurality of carrier frequency offsets; and transmitting data from the first node to one of the plurality of nodes according to a timing determined by the local oscillator.