PN-Radar

PN-Radarnetzwerke mit Phasenrausch-Unterdrückung

In the last years, radar sensors have been widely available for various applications and especially for industrial applications and autonomous driving. Among other factors, this is due to the advancements in semiconductor technologies, making fully integrated sensor frontends possible. The large number of sensor elements used in today´s applications create interesting opportunities by means of establishing a network and cooperative operation in order to enable multi-static measurements. For this purpose, a dedicated communication link could be established between the sensors or the sensors could “see” each other in a multi-static network by receiving each other´s radar signals. The latter has the advantage that no additional resource is required for the communication.

Such sensor networks that do not require an additional communications link will be investigated in this project. Preliminary studies have shown that it is possible to operate multiple radar sensor in such a way that they are able to see each other, even if the sensors are operated incoherently. Incoherent operation is mainly advantageous due to the reduced hardware complexity.  However, the main challenge is the fact that the phase noise of the receivers and the transmitters will not be eliminated in the multi-static operation. In this case, the signal to noise ratio (SNR) of the multi-static radar signals are so much worse than the mono-static case that nothing can be gained by the utilization of all possible radar measurements within the network. A solution is carrier recovery from the transmitted signal on the receiver side, because the recovered carrier will exhibit the same phase noise as the transmit signal, making it possible to cancel the phase noise.

In this project, radar networks in the millimeter-wave frequencies around 240 GHz will be investigated that are modulated with Pseudo-Noise (PN) sequences. All sensors will operate incoherently in the hardware level, while only a rough time synchronization will take place. Carrier recovery will be investigated as a method to cancel the phase noise between each sensor and transmitter pairs in such a network. The network consisting of such digital modulated radars at upper millimeter-wave frequencies will be studied in detail in a simulation environment and will be evaluated and verified by demonstrator experiments.