GRCon21 - Channel Leakage Cancellation for Software Defined Radio (SDR) Narrowband Radar ...

Channel Leakage Cancellation for Software Defined Radio (SDR) Narrowband Radar Interferometry Using GNU Radio presented by Victor Cai and Jon Kraft at GNU Radio Conference 2021 Because the SDR has both an RF transmitter and a receiver integrated in the same module, leakage from transmit into receive path is inevitable. Without proper compensation, the received radar signal is combined with this unintentional leakage signal from the transmit path creating unintended distortion in phase and amplitude. This type of accuracy degradation has been reported in the previous publication when a Multiple Frequency Continuous Wave (MFCW) distance sensing radar was created with SDR.[1] A traditional Pulse or FMCW radar needs 1GHz bandwidth (BW) to achieve 15cm resolution for short range applications, making a typical SDR’s 4-60MHz BW seem far from adequate for distance sensing. However, in this project, a new interferometry radar solution is demonstrated to make short range distance sensing possible using bandwidth-limited SDR. This new concept opens the doors to many short-range radar applications using this low cost SDR technology and will help to overcome the high power and harsh interference associated with traditional ultrawide band radars. Major improvement in distance sensing accuracy has been achieved by introducing two all-software solutions in GNU Radio for leakage cancellation and automatic erroneous result correction. This article will highlight how GNU Radio was used not only as a simulator in the debug phase but also as the end solution to the actual leakage cancellation in the radar operation. https://events.gnuradio.org/event/8/