This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth...This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.展开更多
This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences （DoCS）. In this scheme, input data bit-stream is split into many groups with length M. Ea...This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences （DoCS）. In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utihzed to select one sequence from 2u-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in quadrature phase shift keying （QPSK） mode. In addition, a new method named forward phase correction （FPC） is put forward for carrier recovery. Theoretical analysis and bit-error-ratio（BER） experiment results indicate that the proposed scheme has better performance than the conventional direct sequence spread spectrum（DSSS） scheme both in bandwidth efficiency and processing gain of the receiver.展开更多
We have studied the effect of phase shifted frequency modulation on two level atom with field interaction using Jaynes-Cummings model.Here the frequency of the interacting field is sinusoidally varying with time with ...We have studied the effect of phase shifted frequency modulation on two level atom with field interaction using Jaynes-Cummings model.Here the frequency of the interacting field is sinusoidally varying with time with a constant phase.Due to the presence of phase in the frequency modulation,the variation of population inversion with time is different from the standard case.There are no exact collapses and revivals in the variation of population inversion but it oscillates sinusoidally with time.In coherent field atom interaction the population inversion behaves as in the case of Fock state atom interaction,when frequency modulation with a non zero phase is applied.The study done with squeezed field has shown the same behavior of the population inversion.展开更多
文摘This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.
基金Union Innovation Found of Jiangsu Province(No. BY2009149)
文摘This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences （DoCS）. In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utihzed to select one sequence from 2u-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in quadrature phase shift keying （QPSK） mode. In addition, a new method named forward phase correction （FPC） is put forward for carrier recovery. Theoretical analysis and bit-error-ratio（BER） experiment results indicate that the proposed scheme has better performance than the conventional direct sequence spread spectrum（DSSS） scheme both in bandwidth efficiency and processing gain of the receiver.
文摘We have studied the effect of phase shifted frequency modulation on two level atom with field interaction using Jaynes-Cummings model.Here the frequency of the interacting field is sinusoidally varying with time with a constant phase.Due to the presence of phase in the frequency modulation,the variation of population inversion with time is different from the standard case.There are no exact collapses and revivals in the variation of population inversion but it oscillates sinusoidally with time.In coherent field atom interaction the population inversion behaves as in the case of Fock state atom interaction,when frequency modulation with a non zero phase is applied.The study done with squeezed field has shown the same behavior of the population inversion.
