Electronic devices with frequency scan acceleration

Abstract

An electronic device having a radio is provided. When the radio boots up, the radio may search for downlink signals transmitted by a wireless base station. The device may generate a narrow set of candidate frequencies over which to search for the downlink signals by leveraging a cyclic prefix autocorrelation property of the downlink signals. Each candidate frequency may have a corresponding center frequency offset (CFO) and symbol boundary timing correction that is used when searching over the narrow set of candidate frequencies. To generate the narrow set of candidate frequencies, control circuitry may generate autocorrelated signals from baseband-shifted input signals over a set of different center frequencies and bandwidths. Searching over the narrow set of candidate frequencies may be significantly faster than performing a full raster scan over all frequencies supported by the radio.