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 共查询到17条相似文献,搜索用时 109 毫秒
1.
A novel packet format with non-return-to-zero(NRZ)label and duobinary carrier-suppressed return-to-zero (DCS-RZ)payload is proposed for optical packet switching networks.NRZ label is followed by DCS-RZ payload with a certain guard time.The spectra of the low-rate NRZ label locate around the optical carrier frequency where some parts of the corresponding spectra of the high-rate DCS-RZ payload have been suppressed due to DCS-RZ modulation.At the switching node,the label or payload extraction can be realized simply through an optical bandpass or notch filter respectively.The feasibility of the scheme is verified by the simulation on the famous photonic design platform designed by Virtual Photonics Inc. (VPI).The effects of optical filter bandwidth on the received signal quality are discussed by analyzing bit error rate(BER)and contrast ratio performances.  相似文献   

2.
A label swapping scheme of an optical labeled signal with differential phase shift keying(DPSK) for label at 2.5 Gb/s and pulse position modulation(PPM) for payload at 40 Gb/s is demonstrated by simulation.Power penalties of ~1.8 and ~0.8 dB are achieved for both the payload and label over 80-km single mode fiber(SMF) transmission.This labeling scheme allows the use of four-wave mixing(FWM) in semiconductor optical amplifier(SOA) to perform label erasure,with advantages of transparence for bit rate,high processing rate,simple architecture,and low cost.Label swapping is demonstrated with appropriate penalties of-3.5 and 0.8 dB for PPM payload and new DPSK label,respectively.To further prove the effectiveness of the proposed scheme,label swapping in the case of using 10-Gb/s DPSK label is also investigated with the power penalties of 6 and 2 dB for PPM payload and new DPSK label.  相似文献   

3.
<正>The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated.The factors that affect the transmission performance,such as the FSK tone space,dispersion compensation and coupler split ratio,are studied by numerical simulation.The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.  相似文献   

4.
We experimentally demonstrate 10-Gb/s format conversion from non-return-to-zero (NRZ) to alternatemark-inversion (AMI) using the linear filtering effect of silicon microring resonator. Our discussion and analysis in simulation further show that a 10-Gb/s AMI signal with good quality can be obtained by a resonator with a notch depth larger than 25 dB when the 3-dB bandwidth is 0.4 nm.  相似文献   

5.
A new optical label switching system with coherently detected implicit spectral amplitude code (SAC) labels is proposed in this letter. The implicit SAC labels are recognized using a frequency-swept local light source oscillator. Intensity modulation payloads of 625 Mb/s and 1.25 Gb/s are considered. Label and payload bit error rate (BER) performances are assessed and compared by simulations. The results reveal that, at a BER value of 10 9 , 32.4-dBm label received power can be obtained. In addition, 8.3-dB optical signal-to-noise ratio (OSNR) is obtained when carrying a payload of 625 Mb/s. The label BER value hardly reaches 10 -9 if the payload bit rate is at 1.25 Gb/s; however, a high payload bit rate only has little influence on received payload quality at a BER value of 10 -9 . Finally, a payload of 1.25 Gb/s could obtain 28.2 dBm received power and 9.5-dB OSNR.  相似文献   

6.
A novel differential-phase-shift-keying (DPSK)/pulse-position-modulation (PPM) orthogonal modulation is pro- posed for optical labeling applications, with PPM data as the high-speed payload and DPSK signal as the optical label. The systematic setup for the proposed scheme and research on bit-error rate is presented. The results show that at the bit-error rate of 10-~, the power penalties for 70kin fiber transmission are in the range of 1-3 dB to DPSK label and 5-6 dB to PPM payload in our simulation system. This is under the condition that the large extinction ratio of 18-19 dB is used for the intensity modulators of the PPM payload, with a well received DPSK label. Thus the feasibility of the proposed scheme for all optical transmission networks is clearly verified.  相似文献   

7.
The generation of coherent optical subcarriers based on a concatenated dual-drive Mach-Zehnder intensity modulator(IM) and two phase modulators(PMs) is proposed and experimentally demonstrated.The modulation index and DC bias of PM+IM modulation are theoretically investigated.Theoretical analysis and numerical study are also carried out to examine the proposed scheme.We use 25-GHz RF synchronous sinusoidal signals to drive cascaded two-stage PMs and IM,through which we generate 28 subcarriers with peak power fluctuations less than 4 dB.The measured tone-to-noise ratio of the subcarrier is higher than 40 dB.The experimental results show that for 100-Gb/s polarization multiplexing QPSK signal,the receiver sensitivity of the back-to-back signal is -28.6 dBm,and the power penalty is lower than 1 dB after 100-km transmission at the BER of 1×10-9.  相似文献   

8.
We studied the transmission performance of metro networks employing cascaded thin-film filters (TFFs)for three modulation formats including non-return-to-zero (NRZ), duobinary, and carrier-suppressed RZ (CSRZ). The effects caused by TFFs' dispersion and passband characteristics are investigated for 10- and 40-Gb/s signals, respectively. Simulation results show that the penalty resulted from dispersion can be partially compensated by the passband effects of the cascaded filters. CSRZ is shown to be a preferred format compared with NRZ and duobinary primarily originating from its good back-to-back performance.  相似文献   

9.
<正>We study the performance of an orthogonal modulation system with frequency-shift keying(FSK) label and optical Manchester-coded(MC) payload.Simulation result shows that by introducing an optical MC payload,the available extinction ratio(ER) value of a FSK and intensity modulation(IM) orthogonal modulation system can be improved from 5 to 9 dB for system optimization,exhibiting great advantages over the traditional non-return-to-zero(NRZ) payload.Besides,the bit error rate(BER) characteristics of both label and payload show a more remarkable advantage than that of NRZ coding,verifying itself as a perfect candidate for the payload coding method in orthogonal modulation systems.  相似文献   

10.
All-optical chaotic MQW laser repeater for long-haul chaotic communications   总被引:2,自引:0,他引:2  
We present an all-optical chaotic multi-quantum-well (MQW) laser repeater system to be used in long-haul chaotic communications. Chaotic synchronization is achieved among transmitter, repeater, and receiver. Chaotic repeater communications with a sinusoidal signal of 0.2-GHz modulation frequency and a digital signal of 0.4-Gb/s bit rate are numerically simulated, respectively. Calculation results illustrate that the signals are well decoded by the chaotic repeaters. Its bandwidth and the characteristics at much high bit rate are also analyzed. Simulation shows that the repeater can improve decoding quality, especially in higher bit rate chaotic communications.  相似文献   

11.
A novel packet format with non-return-to-zero (NRZ) label and duobinary carrier-suppressed return-to-zero (DCS-RZ) payload is proposed for optical packet switching networks.NRZ label is followed by DCS-RZ payload with a certain guard time.The spectra of the low-rate NRZ label locate around the optical carrier frequency where some parts of the corresponding spectra of the high-rate DCS-RZ payload have been suppressed due to DCS-RZ modulation.At the switching node,the label or payload extraction can be realized simply through an optical bandpass or notch filter respectively.The feasibility of the scheme is verified by the simulation on the famous photonic design platform designed by Virtual Photonics Inc.(VPI).The effects of optical filter bandwidth on the received signal quality are discussed by analyzing bit error rate(BER)and contrast ratio performances.  相似文献   

12.
We investigate the pattern dependency of the 40-Gb/s optical duobinary signals generated by a 10-Gb/s-rated Mach-Zehnder modulator with four different configurations. These configurations correspond to all possible combinations of a 15-GHz-bandwidth low-pass filter and a 0.24-nm bandwidth optical filter used to shape up the duobinary signals. We compare through experiment the back-to-back sensitivities and transmission performances of the duobinary signals for pseudorandom bit sequence lengths of 27-1 and 231-1. The results show that the combination of the 10-Gb/s-rated modulator and the 0.24-nm optical filter exhibits the best performance in terms of both the receiver sensitivity and pattern dependency owing to the good frequency response of the optical filter.  相似文献   

13.
Z. Dong  J. Yu 《Optics Communications》2009,282(13):2484-4705
Simultaneous wavelength conversion based on four-wave mixing (FWM) for 10-Gb/s NRZ payload and 2.5-Gb/s OFDM label signals in optical switching network is experimentally demonstrated. The dual-pump scheme based on FWM in semiconductor optical amplifier (SOA) is employed and simultaneous wavelength conversion for optical packet with one optical payload of 10-Gb/s non-return-to-zero (NRZ) on-off keying (OOK) signals and one optical label of 2.5-Gb/s OFDM signals are realized. The bit-error-rate performance is evaluated for both payload and label after wavelength conversion.  相似文献   

14.
In this paper, we present an orthogonal labelling scheme using inverted return-to-zero (IRZ) as payload and differential-phase-shift-keying (DPSK) as label. Transmission performances of orthogonal labelling with 40 Gb/s IRZ payload and 10 Gb/s label are evaluated. Simulation results show that orthogonal labelling using IRZ as payload exhibits a much larger extinction ratio margin than that of using return-to-zero (RZ) as payload. The asynchronous effect between payload and label on the transmission performances of orthogonal labelling using IRZ and RZ as payload is evaluated. Simulation results show that the degradation of asynchronous orthogonal labelling using IRZ as payload is relatively worse than that of using RZ as payload. The impact of optical filter bandwidth before receivers is also investigated. Results show that the receiver sensitivities of label for IRZ/DPSK and payloads for both IRZ/DPSK and RZ/DPSK are degraded with the reduction of the filter bandwidth, while the label of RZ/DPSK exhibits an opposite trend.  相似文献   

15.
Modified duobinary return-to-zero (MD-RZ) format is an improvement of optical duobinary (ODB) format.This paper proposes a novel, all-optical method to generate MD-RZ format by using a polarization maintaining fiber loop mirror (PMFLM). Operation principle for all-optical format conversion is theoretically analyzed and the output spectrum is simulated. 40-Gb/s MD-RZ data format generation is experimentally demonstrated.  相似文献   

16.
光双二进制传输系统的性能研究   总被引:4,自引:1,他引:3  
胡辽林  刘增基 《光子学报》2003,32(6):727-730
光双二进制信号的谱宽是传统二进制信号的一半,采用双二进制传输比二进制传输色散限制的中继距离可增加一倍.本文对采用传统光接收机的光双二进制传输系统用MATLAB进行了通信仿真.结果表明:在完全消光条件下,10 Gb/s双二进制信号在常规单模光纤上传输可达160 km,40 Gb/s双二进制信号在非零色散光纤上为30 km,均比二进制增加了一倍;详细考察了消光比对传输的影响,只有消光比大于25 dB时,双二进制相对于二进制传输的优越性才呈现出来.  相似文献   

17.
We propose and numerically investigate a novel high-speed (40-Gb/s and above) optical frequency shift-keying (FSK) transmitter scheme. By optical carrier-suppressed modulation and differential phase-shift-keying (DPSK) to intensity modulation (IM) conversion, only one light source is needed in the proposed scheme to generate high-speed optical FSK signals. By using a Mach-Zehnder modulator (MZM) as phase modulator and an additional delay interferometer (DI) cascaded after the carrier-suppressed MZM to suppress the remaining carrier, the performance of our scheme can compete with the double-light-source counterparts. The transmission performances of the FSK signal generated with the proposed scheme as well as detuning and bandwidth tolerance of the demodulation filter are also carefully investigated. Simulation results show that the proposed FSK generation scheme is very suitable for the next-generation optical access network and optical label switching network. A potential application of our scheme in high-speed passive optical network is proposed.  相似文献   

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