Time-Frequency Bandwidth Product Estimation of Sinusoidal Non-Linear Chirp Keying Scheme

Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some parameter estimation issues over conventional modulation schemes. In this paper, a novel transform termed as Discrete Sinusoidal Frequency Modulation transform(DSFMT) is proposed. Then, the DSFMT of SNCK signal is deduced and classified into three types, based on which, the time-bandwidth product is estimated by the proposed algorithm. Simulation results show that the noise has a signifi cant impact on the localization of the peak value and the time-bandwidth product can be estimated by using local ratio values when.

A novel modulation and direct detection scheme of optical phase shift keying

This paper introduces a new modulation and direct detection scheme of optical phase shift keying (PSK) which is simple and practical in fiber optical communication. A phase modulator is used to modulate a continuous wave (CW) laser source and return-to-zero (RZ) signal that is changed from the initial transmitting information is used to control a phase modulator to form a optical PSK signal. In the receiver terminal, just add a signal delayed a half of one bit to itself so that the initial information can be restored.

A 2Mbps Human Body Communication Transceiver Based on Body Antenna Effect

This paper presents a human body communication(HBC)transceiver for wireless body network applications.The transceiver employs on frequency shift keying(FSK)modulation and op-erates in 40 MHz-60 MHz which is the resonant frequency of the human body as an antenna.It achieves high performance and stability through establish passive microstrip line and via models and active device-models.The proposed transceiver is designed and fabricated by FR4 printed cir-cuit board(PCB)process,the transceiver has the ability of configurable data rate up to 2 Mbps and it achieves-86 dBm receiving sensitivity at 2 Mbps data rate.Meanwhile,the transceiver out-put power dynamics range is 34 dB.Furthermore,with a visual interaction interface,the transceiv-er can be agility use in a variety of scenarios.Its measurements are verified on human body.The result shows that the transceiver has ability to send data from person to person by relying on hu-man body antenna radiation.The transceiver shows great prospect in wireless body area networks(WBAN)for telemedicine and emergency communication.

Iterative Noncoherent Block Detection of Coded MPSK for Cooperative Relay Systems

Maximum likelihood(ML) noncoherent block detection techniques are investigated for block-coded MPSK modulation in cooperative decode-and-forward relay systems over slow fading channels.A decision-directed iterative Viterbi algorithm(IVA) is derived for a suboptimal ML noncoherent detection.Simulation results show that the IVA can approach the error performances of the exhaustive detection method but at a lower complexity.

Silicon high-speed binary phase-shift keying modulator with a single-drive push–pull high-speed traveling wave electrode

We demonstrate binary phase shift keying(BPSK) modulation using a silicon Mach–Zehnder modulator with aπ-phase-shift voltage(Vπ) of-4.5 V.The single-drive push–pull traveling wave electrode has been optimized using numerical simulations with a 3 dB electro-optic bandwidth of 35 GHz.The 32 Gb/s BPSK constellation diagram is measured with an error vector magnitude of 18.9%.

PDM-DPSK-MPPM hybrid modulation for multi-hop free-space optical communication

A hybrid polarization division multiplexed-differential phase shift keying-multipulse pulse position modulation(PDM-DPSK-MPPM) scheme for multi-hop free-space optical(FSO) communication is investigated. The analytical bit error rate(BER) of the proposed system in Gamma-Gamma turbulence channels is derived and verified using computer simulation. The results show that both multi-hop and hybrid modulation schemes are efficient techniques to improve the performance of FSO links. Compared with the traditional binary phase shift keying(BPSK) and MPPM, the hybrid scheme can improve the bandwidth-utilization efficiency and reliability of the system. Compared with the coherent demodulation of PDM-QPSK-MPPM, the system complexity is reduced at the cost of the degradation of BER performance, which can improve the practicality of hybrid modulation technology in FSO system.

Frequency-octupled phase-coded signal generation based on carrier-suppressed high-order double sideband modulation

An approach for photonic generation of a frequency-octupled phase-coded signal based on carrier-suppressed high-order double sideband modulation is proposed and experimentally demonstrated. The key component of the scheme is an integrated dual-polarization quadrature phase shift keying modulator, which is used to achieve the carrier-suppressed high-order double sideband modulation. At the output of the modulator, two fourth-order optical sidebands are generated with the optical carrier suppressed. After that, a Sagnac loop incorporating a fiber Bragg grating and a phase modulator is employed to separate the two optical sidebands and phase modulate one sideband with a binary coding signal. The approach features large carrier frequency tuning range for the generated phase-coded signal from several megahertz to beyond the W-band. A proof-of-concept experiment is carried out. The 2 Gbit/s phase-coded signals with frequencies of 16.48, 21.92, and 29.76 GHz are generated.

Simultaneous wireless information and power transfer transmitting architecture based on asynchronous space-time-coding digital metasurface[Invited]

Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.However,the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency.This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface(ASTCM).High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface.We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification,which is therefore believed to have great potential in wireless communications and the IoT devices.

Tracking structure suitable for L6 signal

A tracking structure suitable for L6 signal of quasi-zenith satellite system(QZSS) was proposed in order to track the L6 signal without other frequency assistance. Moreover, the tracking structure does not change the receiver’s hardware structure. The main difference between the proposed and the traditional tracking structure lies in the generation of local codes of E,P and L branches. The method of local code generation is designed in a two-stage manner. The first stage is the generation of the P branch local code with fast fouriertransform(FFT). In the second stage, the local codes of the E and L branches are obtained with the code-chip interval. The tracking structure can track and decode L6 signal separately, and track code shift keying(CSK)modulated signal as well. The structure was verified using both simulation data, generated in different conditions, and actual data obtained from QZSS satellites respectively. The results show that the improved tracking loop is able to track L6 signal without other frequency assitance. Furthermore, the biterror ratio(BER) of L6 tracking algorithm is lower than that of L1C/A assist L6 algorithm, when the Doppler remains a constant and reed solomn(RS)encode are applied. To be more specific, with the proposed structure the BER decreased by 11.40%, 17.07%, 15.00%, 11.15%, 5.19% when carrier to noise ratio(CNR) is 36-40 dB·Hz.

A WDM-PON with DPSK modulated downstream and OOK modulated upstream signals based on symmetric 10 Gbit/s wavelength reused bidirectional reflective SOA

We investigate a wavelength-division-multiplexing passive optical network(WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying(DPSK) downstream signals and on-off keying(OOK) upstream signals,respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier(RSOA) as an intensity modulator at the optical network unit(ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio(ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate(BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.

Average bit error rate performance analysis of subcarrier intensity modulated MRC and EGC FSO systems with dual branches over M distribution turbulence channels

Based on the space diversity reception,the binary phase-shift keying(BPSK) modulated free space optical(FSO) system over Málaga(M) fading channels is investigated in detail.Under independently and identically distributed and independently and non-identically distributed dual branches,the analytical average bit error rate(ABER) expressions in terms of H-Fox function for maximal ratio combining(MRC) and equal gain combining(EGC) diversity techniques are derived,respectively,by transforming the modified Bessel function of the second kind into the integral form of Meijer Gfunction.Monte Carlo(MC) simulation is also provided to verify the accuracy of the presented models.

Low-loss high-extinction-ratio single-drive push-pull silicon Michelson interferometric modulator

We demonstrate a high-speed silicon carrier-depletion Michelson interferometric（MI）modulator with a low onchip insertion loss of 3 dB.The modulator features a compact size of 〈1 mm2 and a static high extinction ratio of 〉30 dB.The Vπ·Lπ of the MI modulator is 0.95–1.26 V·cm under a reverse bias of -1 to-8 V,indicating a high modulation efficiency.Experimental results show that a 4-level pulse amplitude modulation up to 20 Gbaud is achieved with a bit error rate of 6×10-3,and a 30 Gb/s binary phase-shift-keying modulation is realized with an error vector magnitude of 25.8%.