In the D2D communication mode, UEs 210 and 220, whether within network coverage or in partial or outside network coverage, would essentially be operating in a form of TDD mode because D2D devices would transmit and listen on the same carrier subject to half-duplex constraints. Therefore, a challenge rises to accommodate the Tx/Rx switching time of about a length of 624 T_s, which is about 20.3 microseconds (μs) as one T_s is 1/(15000*2048) seconds.

Further, UEs 210 and 220 may need to consider the AGC setting time in the D2D communication mode. The AGC operations in D2D communications are different from those in cellular operations where UEs receive packets only on DL carrier (FDD) or subframes (TDD). In the D2D communications, different UEs may be frequency-multiplexed for different subframes. Further, subframe sets may also depend on the use of different forms of multiple transmission time interval (TTI) transmissions for D2D discovery and communications. Due to the random nature of AGC operations in the D2D communications, UE 210 or 220 may need different AGC setting times for different subframes.

In various embodiments, the communication module 222 may be coupled with the antennas 228 to facilitate over-the-air communication of signals between UE 220 and UE 210 or another UE. For example, the transceiver circuitry 224 may be configured to provide various signal processing operations on the signal to the antennas 228 with suitable characteristics. In various embodiments, operations of the transceiver circuitry 224 may include, but are not limited to, filtering, amplifying, storing, modulating, demodulating, transforming, etc.