Low complexity image rejection demodulator for bluetooth LE applications

This paper presents a low complexity demodulator architecture which can significantly suppress the image interference in low IF receivers. Compared to other image rejection architectures, the power consumption and design complexity are greatly reduced. On the other hand, the multiplier free MUX based frequency shifter for baseband signal convertor and reference generator are implemented to highly reduce the calculation complexity. In addition, the symmetric LMS filter with single coefficient is used for the mismatch cancellation. Measurement results show the receiver using proposed technique gains significantly robustness against the image interference.