Full duplex operation in a wireless network
Multiple wireless devices in a network perform full duplex communication in which the transmission path and receiving path are spatially separated to allow simultaneous transmission and receiving. The wireless devices can either be controlled using a centralized, or point, coordination function or a distributed coordination function. A full-duplex wireless device senses the medium during transmission by itself and selectively continues the transmission when a signal is sensed on the medium. A full-duplex wireless device measures signal being transmitted by its transmitter and estimates parameters that can be used to cancel the contribution of the locally transmitted signal to the locally received signal concurrently being received during the transmission. The transmit antenna and the receive antenna of a full-duplex wireless device can be configured to be spatially isolated from each other to minimize interference between the antenna functions.
1. A method for detecting and avoiding transmission collisions over a medium in a wireless communication system, comprising:
sensing the medium for a transmission;
transmitting, when no transmission is sensed on the medium, a first frame of data on the medium;
continuing sensing the medium during transmission of the first frame of data;
receiving, when a transmission is sensed while transmitting the first frame of data, a second frame of data; and
controlling transmission of the first frame of data selectively based on whether or not the second frame of data was successfully received.
2. The method of claim 1 , wherein the transmitting is performed using a transmit antenna and wherein the receiving is performed using a receive antenna, and wherein the transmit antenna and the receive antenna are spatially isolated from each other.
3. The method of claim 1 , further comprising:
estimating, a contribution by the transmission of the first frame of data, to a received signal; and
subtracting, from the received signal, the estimated contribution, to receive the second frame of data.
4. A method for detecting and avoiding collisions over a medium in a wireless communication system, comprising:
sensing, in a first time interval, the medium for a transmission;
when no transmission is sensed on the medium, transmitting, in a second time interval temporally after the first time interval, a first frame of data on the medium;
continuing sensing the medium during transmission of the frame in the second time interval;
when a transmission is sensed during the second time interval, then stopping transmission of the first frame of data.
5. The method of claim 4 , wherein the transmitting is performed using a transmit antenna and wherein the receiving is performed using a received antenna, and wherein the transmit antenna and the receive antenna are spatially isolated from each other.
6. The method of claim 4 , further comprising:
estimating, a contribution by the transmission of the first frame of data, to a received signal; and
subtracting, from the received signal, the estimated contribution, to receive the second frame of data.