Random access for low-duty-cycle time division duplexing in wireless communications

Abstract

Methods, systems, and devices for wireless communications are described that provide for random access techniques for low duty-cycle time division duplexing (TDD) communications. Random access preamble transmissions may use transmission resources associated with one or more preamble repetition units (PRUs), where a PRU may at least partially overlap with transmission resources that are not valid for a transmission. In such cases, all or a portion of the random access transmissions of the PRU may be postponed to a next valid uplink communication resource. Postponement of random access transmissions may be performed at a symbol-group level for symbol groups within a PRU, or at a PRU level. Further, radio network temporary identifiers (RNTIs) associated with random access transmissions may be identified based on a system frame associated with an initial transmission occasion of the random access transmission, or the postponed transmission occasion.