On Hartley Image rejection receivers and adaptive sinusoidal interference cancellation in automotive wireless links

Spurious-free Dynamic Range (SFDR) of frequency sources such as local oscillators in radio has a profound effect on the minimum signal strength that can be detected. Greater the level of unwanted spurs the more difficult it is to detect an incoming signal in the presence of existing interferers and minimum signal/noise ratio at the demodulator input. Taylor series based Direct Digital Synthesis (DDS) produces an SFDR of around 74dB. The proposed architectures in this paper attempt to improve the SFDR by using a Hartley Image suppressor and using a adaptive sinusoidal interference canceller. The resultant improvement in SFDR is around 45 dB by using the Hartley image suppressor and 40dB using the adaptive interference canceller. The two proposed spur suppression techniques are compared in terms of dynamic power, realized noise floor and hardware complexity.