This paper presents a wideband frequency-shift keying （FSK） demodulator suitable for a digital data transmission chain of wireless neural stimulation microsystems such as cochlear implants and retinal prostheses. Th...This paper presents a wideband frequency-shift keying （FSK） demodulator suitable for a digital data transmission chain of wireless neural stimulation microsystems such as cochlear implants and retinal prostheses. The demodulator circuit derives a constant frequency clock directly from an FSK carrier, and uses this clock to sample the data bits. The circuit occupies 0.03 mm^2 using a 0.6 μm, 2M/2P, standard CMOS process, and consumes 0.25 mW at 5 V. This circuit was experimentally tested at transmission speed of up to 2.5 Mbps while receiving a 5-10 MHz FSK carrier signal in a cochlear implant system.展开更多
The decoupled coherent Maximum Likelihood (ML) detection algorithm presented in this letter can sharply reduce the complexity of the receiver as well as provide better error performance under the precondition that cha...The decoupled coherent Maximum Likelihood (ML) detection algorithm presented in this letter can sharply reduce the complexity of the receiver as well as provide better error performance under the precondition that channel should be estimated first. Considering the bandwidth inefficiency of Frequency Shift Keying (FSK), the acquisition of channel state information through training sequences will further decrease the transmission efficiency. This letter presents a blind channel estimation algorithm based on noise subspace theory which can acquire channel information without any training symbols. The simulation shows that the algorithm brings about fewer channel estimation errors while the frequency efficiency can be increased.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. G2000036508) and the National Natural Science Foun-dation of China (No. 60475018)
文摘This paper presents a wideband frequency-shift keying （FSK） demodulator suitable for a digital data transmission chain of wireless neural stimulation microsystems such as cochlear implants and retinal prostheses. The demodulator circuit derives a constant frequency clock directly from an FSK carrier, and uses this clock to sample the data bits. The circuit occupies 0.03 mm^2 using a 0.6 μm, 2M/2P, standard CMOS process, and consumes 0.25 mW at 5 V. This circuit was experimentally tested at transmission speed of up to 2.5 Mbps while receiving a 5-10 MHz FSK carrier signal in a cochlear implant system.
文摘The decoupled coherent Maximum Likelihood (ML) detection algorithm presented in this letter can sharply reduce the complexity of the receiver as well as provide better error performance under the precondition that channel should be estimated first. Considering the bandwidth inefficiency of Frequency Shift Keying (FSK), the acquisition of channel state information through training sequences will further decrease the transmission efficiency. This letter presents a blind channel estimation algorithm based on noise subspace theory which can acquire channel information without any training symbols. The simulation shows that the algorithm brings about fewer channel estimation errors while the frequency efficiency can be increased.
