I am reading some papers and in one paper, the working of an integrating receiver is mentioned to remove (periodic) interference from the received signal. The paper explains the working as such:
The integrating receiver utilizes the constant amplitude of the data signal and the periodic time-varying amplitude of the sinusoidal interference signal to separate them by integrating them over a fixed period of time. The constant amplitude data keeps on adding up as it is integrated over time. However, the periodic sinusoidal interference still remains a sinusoid even after integration. The periodic zero crossing of these sinusoids enables the possibility of sampling at appropriate instants to have zero integrated interference.
The I-DDR receiver utilizes the integration, followed by periodic sampling, on periodic interference affected constant amplitude nonreturn to zero (NRZ) data to achieve interferencerobust operation through signal interference separation in the time domain.
S. Maity, B. Chatterjee, G. Chang and S. Sen, "BodyWire: A 6.3-pJ/b 30-Mb/s −30-dB SIR-Tolerant Broadband Interference-Robust Human Body Communication Transceiver Using Time Domain Interference Rejection," in IEEE Journal of Solid-State Circuits, vol. 54, no. 10, pp. 2892-2906, Oct. 2019, doi: 10.1109/JSSC.2019.2932852.
Now I have the following questions:
- You integrate the data signal, now you have the data signal added over a period of time. So? What can I do with that?
- If we integrate the interference signal at its zero crossings, then we would have a integration value of ~zero over a period of time. So we have "nothing." How can we use that to separate the interference signal from the data signal?
I feel like I am missing the point of this integrating receiver a bit but maybe someone could explain it to me.