A high-resolution burst-mode laser transmitter with fast and accurate level monitoring for 1.25 Gb/s upstream GPONs

An innovative burst-mode laser transmitter (BM-TX) is presented for gigabit-capable passive optical network (GPON) upstream transmission at 1.25 Gb/s. The laser bias and modulation current each can reach 80 mA with a resolution of 0.1 mA providing a total drive current up to 160 mA. Both currents are generated by 10-bit current steering digital-to-analog converters (DACs), the architecture of which is specially adapted to yield a monotonic current setting at settling times below 12.8 ns. Tests show that fast automatic power control (APC) can stabilize and track the launched optical power with a tolerance of less than 1 dB over a wide temperature range for outdoor operation. The APC only requires a straightforward calibration of the "0" and the "1" level at room temperature. Optical level monitoring on strings of four consecutive "0" bytes and two consecutive "1" bytes at 1.25 Gb/s is demonstrated. APC based on such short strings of data has not been shown before. The circuits have been designed in a 0.35 /spl mu/m SiGe BiCMOS process. Experimental results show that this dc-coupled BM-TX meets the specifications of the recently approved ITU-T Recommendation G.984.2 supporting an intelligent power leveling mechanism (PLM).     

High-speed active-input cascode current mirror

A high-speed active-input cascode current mirror is presented. The proposed configuration combines a high output impedance with the high-frequency performance of a source- or emitter-driven active-input topology. Simulation results in a 0.35 /spl mu/m SiGe BiCMOS are presented to demonstrate the validation of the proposed current mirror. A much higher (about 30 to 40 times) output impedance is achieved, with no degradation in the high-frequency behaviour compared to conventional emitter-driven active-input current mirrors, without increasing the power consumption. The proposed configuration can be applied to both bipolar and CMOS technology.     

2.5 V passive CMOS mixer with 20 dBm P1 dB compression

A passive CMOS downconversion mixer with LO buffer is presented in 0.25 μm SiGe BiCMOS using a 2.5 V supply. With a 60 MHz RF signal input, measurements show that the conversion loss is 2.9 dB, the input-referred 1 dB compression point is 20 dBm and the inputreferred noise is 2146.8 dBm/Hz. Compared to conventional NMOS mixers, the 1 dB compression point is improved by 9.7 dB. The tradeoffs and the design of the LO buffer, which has a strong impact on the intermodulation distortion, are also presented.     

Development of GPON upstream physical-media-dependent prototypes

This paper presents three new gigabit-capable passive optical network (GPON) physical-media-dependent (PMD) prototypes: a burst-mode optical transmitter, an avalanche photodiode/transimpedance amplifier (APD-TIA), and a burst-mode optical receiver. With these, point-to-multipoint (P2MP) upstream transmission can be realized in a high-performance GPON at 1.25 Gb/s. Performance measurements on the new burst-mode upstream PMD modules comply with GPON uplink simulations. The laser transmitter can quickly set and stabilize the launched optical power level over a wide temperature range with better than 1-dB accuracy. A burst-mode receiver sensitivity of -32.8 dBm (BER=10/sup -10/) is measured, combined with a dynamic range of 23 dB at a fixed APD avalanche gain of 6. Full compliance is achieved with the recently approved ITU-T Recommendation G.984.2 supporting an innovative overall power-leveling mechanism.     

Mixed analogue/digital phase picking algorithm in oversampling burst-mode clock phase alignment

A novel mixed analogue/digital design of a phase picking algorithm in an oversampling clock phase recovery is presented. The proposed approach results in reduced processing time, improved integrability with analogue front-end and low noise generation. Simulations of a 10 Gbit/s burst-mode clock phase alignment circuit in a 0.25 m SiGe BiCMOS process, show a simulated processing delay of only 280 ps.     

OSNR Penalty Imposed by Linear In-Band Crosstalk Caused by Interburst Residual Power in Multipoint-To-Point Networks

We present an analysis of linear in-band crosstalk in high split long reach wavelength/time-division-multiplexing passive optical networks (WDM-TDM PONs). In this letter, a mathematical model is deducted for the first time to calculate optical signal-to-noise ratio penalties due to in-band crosstalk in multipoint-to-point networks. The network performance can be perturbed by in-band crosstalk caused by power leakages from burst-mode optical network units (ONUs) in off-state. Our study results show that the leaked powers in upstream ONU transmitters can have an impact on the achievable split factor of WDM-TDM PONs. Furthermore, the performance limitations caused by aggregated interburst residual power are discussed.     

Efficient Parallelization of Polyphase Arbitrary Resampling FIR Filters for High-Speed Applications

This article describes a method for increasing the sampling rate of efficient polyphase arbitrary resampling FIR filters. An FPGA proof of concept prototype of this architecture has been implemented in a Xilinx Kintex-7 FPGA which is able to convert the sampling rate of a signal from 500 MHz to 600 MHz. This article compares this new architecture with other best known efficient resampling architectures implemented on the same FPGA. The area usage on the FPGA shows that our proposed implementation is very proficient in high bandwidth applications without requiring significantly more resources on the FPGA. A theoretical calculation of the resampling error introduced on a modulated data stream is provided to evaluate the new architecture against other existing resampling architectures.     

用于433 MHz ISM频带的低功耗超再生接收器

设计师经常选择超再生接收器(super-regenerative receiver)——尽管它的频率不稳定,选择性较差——用于那些以功耗为主要问题的电池供电短距离无线应用,例如远程无钥匙进入系统,汽车警报、生物医学监视器、传感器网络、计算机外设     

A 1.25-gb/s burst-mode receiver for GPON applications

This paper presents a 1.25-Gb/s burst-mode receiver (BMRx) for upstream transmission over gigabit passive optical networks (G-PONs). The dc-coupled receiver uses a unique arrangement of three limiting amplifiers to convert the bursty input signal to a current mode logic output signal while rejecting the dc offset from a preceding transimpedance amplifier. Peak detectors extract a decision threshold from a sequence of 12 successive nonreturn-to-zero (NRZ) 1's and 12 successive NRZ 0's received at the beginning of each packet. Automatic compensation of the remaining offsets of the BMRx is performed digitally via digital-to-analog converters. The chip was designed in a 0.35-/spl mu/m SiGe BiCMOS process. The receiver contains an APD with a gain of 6 and a transimpedance amplifier and shows a sensitivity of -32.8 dBm and a dynamic range of 23.8 dB. A sensitivity penalty of 2.2 dB is incurred when a packet with average optical power of -9 dBm precedes the packet under consideration, the guard time between the packets being 25.6 ns. The BMRx includes activity detection circuitry, capable of quickly detecting average optical levels as low as -35.5 dBm. The performed measurements prove that the receiver meets the G-PON physical media dependent layer specification defined in ITU-T Recommendation G.984.2.     

Simulations and Experiments on the Effective Optical Gain of FEC in a GPON Uplink

This letter studies the effective optical gain of Reed-Solomon (RS) forward-error correction (FEC) in a burst-mode gigabit passive optical network (GPON) uplink. Numerical simulations are made of the performance of an RS (255, 239) FEC code. For the first time, FEC performance is measured in a 1.25-Gb/s burst-mode GPON uplink in the presence of mode partition noise (MPN). Measurements show that the effective optical gain of RS (255, 239) can be considerably higher than 2.7 dB when MPN dominates