The application relates to a portable electronic system comprising a first electronic device and an auxiliary device. The first electronic device comprises a first antenna defining a first spatial direction, and a first wireless unit operationally coupled to the first antenna. The auxiliary device comprises a second antenna defining a second spatial direction, the second antenna comprising a multitude of antenna elements, each defining a specific spatial direction, a second wireless unit operationally coupled to the second antenna, a direction detector configured to provide a direction-signal indicating an estimate of a current value of said second spatial direction relative to a reference direction, and a control unit configured to selectively control the connection of said multitude of antenna elements of the second antenna to said second wireless unit based on said direction-signal from the direction detector. Thereby a wireless link between a hearing assistance device and an auxiliary device can be optimized.