In some embodiments, the RF repeater may determine which set of RF signals to retransmit and which set of RF signals not to retransmit based on authentication. In some of these embodiments, the RF repeater may include authentication circuitry 104 to authenticate the received RF signal based on one or more authentication features 114 and retransmission determination circuitry 106 to determine whether or not to retransmit the received RF signal based on one or more retransmission features 116. In these embodiments, the received RF signal may be authenticated based on a first set of features 114 (e.g., frequency error or offset) and the decision to retransmit may be based on a second set of features 116. In some of these embodiments, the memory may store the identities or characteristics of devices whose signals will be retransmitted.

In some embodiments, the RF repeater may determine the one or more authentication features 114 using in-phase (I) and quadrature-phase (Q) samples generated from the received RF signal. In these embodiments, the one or more authentication features 114 comprise an error vector magnitude of the I and Q samples (e.g., an I-Q symbol error) and a local-oscillator (LO) signal presence in the received RF signal, although the scope of the embodiments is not limited in this respect. In these embodiments, the RF repeater may authenticate the received RF signal when the error vector magnitude of the I and Q samples is below a predetermined threshold and/or based on a ratio of the LO signal level to the RF signal level (e.g., a ratio or quantity of the LO that may be present in the received RF signal).