QUALCOMM Incorporated
Listen-before-talk schemes for directional communications

Abstract:

Methods, systems, and devices for wireless communications are described. In some systems, wireless devices operating in an unlicensed radio frequency spectrum band may perform directional listen-before-talk (LBT) procedures to gain access to a channel. In a beam-shrinking scheme for directional LBT, a wireless device may start an LBT procedure using a first beam (e.g., a wide beam). If the clear channel assessment (CCA) fails for the first beam (e.g., due to directional interference), the device may switch the LBT procedure to a second beam (e.g., a narrower beam). Depending on the direction of the interference source, the second beam may result in a successful LBT procedure. In a beam sweeping scheme for directional LBT, a wireless device may perform concurrent LBT over multiple narrow beams. If any beam of the set of beams detects frequent or continuous interference, the device may drop that beam from the concurrent LBT procedure.