Apple Inc.

Tiberiu Muresan

Mohit Narang

Tarik Tabet

Sanjeevi Balasubramanian

Shiva Krishna Narra

Lydi Smaini

Dhruv Khati

Anjaneyulu Maganti

Zhu Ji

Jia Tang

Vijay Gadde

Sharad Garg

Vijendrakumar K Ashiwal

Dikshit Garg

Vijay Venkataraman

Pengkai Zhao

Tarakkumar G Dhanani

A wireless device may comprise antennas and a processor configured to cause the wireless device to determine preferred antenna ports for at least one primary component carriers (PCCs) and at least one secondary component carriers (SCCs) based on performed downlink measurements of antenna ports. The wireless device may further determine support capabilities of the wireless device and perform computations using additional measurements of the antenna ports. Based on the computations, the wireless device may assign the preferred antenna ports to the PCCs and SCCs and perform uplink transmission using the assigned antenna ports.

Uplink carrier aggregation antenna contention resolution

In a method of device-to-device communication, a user device initially sends an emergency message repeatedly at a first repeating frequency. When a specified number acknowledgement (ACK) messages are received, the user device sends the emergency message repeatedly at a reduced repeating frequency. The repeating frequency may be further reduced when more ACK messages are received.

Enhanced procedures for sending emergency messages to multiple mobile devices

A power control method for device-to-device communication includes dynamically backing off transmit power value for synchronization signals and discovery messages when the distance between the two devices is less than a pre-determined threshold. The threshold distance may correspond to a distance where the receive power may exceed a pre-determined value. Embodiments may loop the transmit power of synchronization signals between a default transmit power value and backed-off values in consecutive slots of each frame.

Power control for synchronization and discovery messages in D2D communication

The present disclosure relates to opportunistically selecting an antenna in an electronic device having multiple antennas. A baseband processor of the electronic device may connect to a first cellular tower providing cellular service at a first frequency using a first antenna of the electronic device. The baseband processor may then receive an indication of a handover event to a second cellular tower operating at a second frequency. The baseband processor may determine signal measurements of the second cellular tower for each antenna of the electronic device that is capable of operating at the second frequency. The baseband processor may execute a handover to the second cellular tower using the antenna associated with the best performing signal measurements. In this manner, an antenna may be opportunistically selected based on performance of the antenna, improving operation of the electronic device and quality of cellular service.

Systems and methods for opportunistic antenna selection

In a method of device-to-device communication, efficient power management is provided when a primary device has a low battery level. The primary device can send synchronization signals and discovery messages to secondary devices by looping through a sequence of transmit power values in a sequence of consecutive frames, where the sequence of transmitting values includes a default power value and a reduced power value.

Adaptive transmit power for efficient battery management

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San Jose, CA, United States of America

Tiberiu Muresan