A method of improving SFDRs of 1-bit signals for a monobit receiver

Abstract

This paper proposes a method to improve the spurious-free dynamic ranges (SFDRs) of 1-bit sampled signals greatly, which is very beneficial to multi-tone signals detection. Firstly, the relationship between the fundamental component and the third harmonic component of 1-bit sampled signals is analyzed for determining four contiguous special frequency bands, which do not contain any third harmonics inside and cover 77.8% of the whole Nyquist sampling frequency band. Then, we present a special 4-channel monobit receiver model, where appropriate filter banks are used to obtain four desired pass bands before 1-bit quantization and each channel can sample and process sampled data independently to achieve a good instantaneous dynamic range without sacrificing the real-time performance or computing resources. The simulation results show that the proposed method effectively eliminates the effect of the most harmonics on SFDRs and the mean SFDR is increased to to 20 dB. Besides, the multi-signals simulation results indicate that the maximum amplitude separation (dynamic range) of two signals in each channel is 12 dB while the proposed monobit receiver can deal with up to eight simultaneous arrival signals. In general, the designing method proposed in this paper has a potential engineering value.