Automotive antenna diversity system for satellite radio with high phase accuracy in low snr-scenarios

For a fast scan-phase satellite radio antenna diversity system a noise cancellation method is presented for significant improvement of audio availability at low signal-to-noise ratio conditions. An error analysis of level and phase detection within the diversity system in the presence of noise leads to a method of error correction based on a priori knowledge of the system's noise floor. The corresponding noise correction is described and applied in a hardware example of an SDARS antenna diversity circuit for fast fading conditions. Measurement results of signals from test drives in real fading scenarios using all available satellite signals are shown, comparing a diversity reception system with noise correction, the same system without noise correction and a single antenna reception system with each other. Using this new method in fast multipath fading driving scenarios underneath dense foliage with a low signal-to-noise ratio of the antenna signals, a further reduction in audio mute time by one order of magnitude is achieved due to the diversity system.