Title :
A Non-Coherent DPSK Data Receiver With Interference Cancellation for Dual-Band Transcutaneous Telemetries
Author :
Zhou, Mingcui ; Yuce, Mehmet ; Liu, Wentai
Author_Institution :
Dept. of Electr. Eng., Univ. of California, Santa Cruz, CA
Abstract :
A dual-band telemetry, which has different carrier frequencies for power and data signals, is used to maximize both power transfer efficiency and data rate for transcutaneous implants. However, in such a system, the power signal interferes with the data transmission due to the multiple magnetic couplings paths within the inductive coils. Since the power level of the transmitted power signal is significantly larger than that of the data signal, it usually requires a high-order filter to suppress the interference. This paper presents a non-coherent DPSK receiver without a high-order filter that is robust to the interference caused by the power carrier signal. The proposed scheme uses differential demodulation in the analog domain to cancel the interference signal for a dual-band configuration. The data demodulation also uses subsampling to avoid carrier synchronization circuits such as PLLs. The experimental results show that the demodulator can recover 1 and 2 Mb/s data rates at a 20 MHz carrier frequency, and it is able to cancel an interference signal that is 12 dB larger than the data signal without using complex filters. The demodulator is fabricated in a 0.35 mum CMOS process, with a power consumption of 6.2 mW and an active die area of 2.6times1.7mm2.
Keywords :
CMOS integrated circuits; biomedical telemetry; demodulation; differential phase shift keying; interference suppression; CMOS process; differential demodulation; dual-band transcutaneous telemetry; interference cancellation; multiple magnetic couplings; noncoherent DPSK data receiver; power 6.2 mW; power transfer efficiency; size 0.35 micron; subsampling; transcutaneous implants; Data communication; Demodulation; Differential quadrature phase shift keying; Dual band; Filters; Frequency; Implants; Interference cancellation; Magnetic separation; Telemetry; Bandpass sampling; data telemetry; differential phase shift keying (DPSK); dual-band; inductive coupling; interference cancellation; neural implants; non-coherent; subsampling; transcutaneous;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2008.2001881