Kapsch Trafficcom Ag

Markus Krapfenbauer

Robert Povolny

Johan Rogö

Stefan Schidl

Heinz Liebhart

Johan Rogo

A method for calibrating a single sideband (SSB) receiver, comprising: a) adjusting a mutual phase shift of I- and Q-signals to a first phase shift value; b) feeding a first, a second and a third test signal having a predetermined phase offset to an input to obtain respective SSB signals, and measuring a first and a second phase difference therefrom; c) calculating a first phase error on the basis of the first and second phase differences; d) repeating steps a)-c) with a second phase shift value to obtain a second phase error; and e) calibrating the SSB receiver by using that one of the first and second phase shift values that has yielded the smaller one of the first and second phase errors.

Method for calibrating an SSB receiver

Described are an on board unit (OBU) and a method to control an OBU within a communication zone of a road side unit (RSU), said OBU can be set into an active mode and a sleep mode. Said OBU is set into sleep mode upon receiving a release command from said RSU, and the OBU electronics are shut down so no or a minimum of power is consumed, and is set into active mode when entering said communication zone. A communication unit of said OBU is thereby powered such that the OBU can communicate with said RSU. Said OBU can be set into a tracking mode by said RSU, whereby in said tracking mode at least said communication unit is shut down and a timer is activated in said OBU, such that said OBU can restart said communication unit within a specified time limit from when it is shut down.

Growing community of inventors

Vienna, Austria

Markus Krapfenbauer