Abstract: Methods, systems, and devices for wireless communications are described. Communication devices may perform secret key generation using a set of line-of-sight (LOS) communication modes to secure a physical channel. For example, a first device and a second device may communicate a set of reference signals over the physical channel using a set of LOS communication modes. The first device and the second device may generate a secret key based on the set of LOS communication modes, for example, by using information associated with the set of LOS communication modes to compute the secret key using a key derivation function that outputs the secret key. The first device and the second device may secure the physical channel by encrypting signaling between the first device and the second device with the secret key and communicating the signaling over the physical channel using LOS communications.

Abstract: Methods, systems, and devices for wireless communication are described to estimate interference for concurrent uplink and downlink communications based on an indication of one or more one or more characteristics of an interfering uplink signal communicated between a base station and a second user equipment (UE). The base station or the second UE may transmit, to a first UE, an indication of one or more characteristics of an uplink signal, such as a baseband of the uplink signal or one or more parameters of the uplink signal. The first UE may use the characteristic(s) of the uplink signal to estimate the baseband of the uplink signal and cancel interference associated with the uplink signal. For example, the first UE may use the baseband signal to estimate the interference and may subtract the estimated interference from a downlink signal received at the first UE.

Abstract: Methods, systems, and devices for wireless communications are described. In a wireless communications system, a user equipment (UE) may receive control signaling indicating a first semi-static configuration for transmitting uplink signaling and a second semi-static configuration for receiving downlink signaling. In some cases, the UE may operate using half-duplex communications and may monitor for a transmission direction conflict between the first semi-static configuration and the second semi-static configuration during a transmission time interval. The UE may communicate, according to a priority rule, one of an uplink signal in accordance with the first semi-static configuration or a downlink signal in accordance with the second semi-static configuration during the transmission time interval based on the monitoring. Additionally, or alternatively, the UE may drop one of the uplink signal or downlink signal according to the priority rule.

Abstract: Methods, systems, and devices for wireless communications are described. Generally, a base station may dynamically and reliably indicate that pending transmissions are part of a full duplex operation via downlink control information (DCI) designs described herein. For example, a base station may transmit, to a user equipment (UE) a DCI including no more than one downlink grant and no more than one uplink grant for a full duplex operation. In some examples, the base station may transmit a first-stage DCI including partial information, and second-stage DCIs including full uplink and downlink grants for a full duplex operation. In some examples, the base station may configure periodic or semi-periodic uplink and downlink resources that may overlap in time, and may dynamically indicate, to the UE, whether the overlapping uplink and downlink resources are scheduled for a full duplex operation.