PROPAGATION OVER PARABOLIC TERRAIN: ASYMPTOTICS AND COMPARISON TO DATA

  • Chizhik D.
  • Drabeck L.
  • Macdonald W.

Analysis of radio propagation over varying, clutter-covered terrain was carried out aiming at prediction of power received by a terminal immersed in clutter, with the transmitter placed above clutter. The need for such prediction arises, for example, in planning and assessing coverage and interference in radio communications. Following a general ...

NONUNIFORM LINEAR REGRESSION WITH BLOCK-WISE SAMPLE-MINIMUM PREPROCESSING

  • Hadzic I.
  • Morgan D.

We analyze the statistical properties of slope estimates obtained from linear regression with sample-minimum Erlang variates. The sample-minimum of sequential blocks has the effect of introducing nonuniform time samples. We show that this nonuniformity has negligible effect on the slope estimate variance, but introduces a spurious low-frequency component in the ...

DIGITAL PREDISTORTION FOR POWER AMPLIFIERS USING SEPARABLE FUNCTIONS

  • Jiang H.
  • Wilford P.

This paper is concerned with digital predistortion for linearization of RF high power amplifiers (HPAs). It has two objectives. First, we establish a theoretical framework for a generic predistorter system, and show that if a postdistorter exists, then it is also a predistorter, and therefore, the predistorter and postdistorter are ...

21 DB GAIN 87 LOW-NOISE AMPLIFIER USING 0.18?M SIGE BICMOS

  • Baeyens Y.
  • Chen Y.
  • Lin J.

The performance of a single-ended two-stage high gain low-noise amplifier (LNA) fabricated in a low-cost 200 GHz fT and fmax 0.18 ¿m SiGe BiCMOS technology is presented. The LNA shows a maximum power gain of 21 dB at 87 GHz with a 3 dB bandwidth from 81 to 92.6 GHz. ...

PHOTOEMISSION OF SI 1S?2PZ TRANSITION IN GAAS/ALGAAS QUANTUM WELL FOR ZERO-DIMENSIONAL STATES INFRARED DETECTION

  • Antoni T
  • Berger V.
  • Carras M.
  • Marcadet X.
  • Vinter B.

Intersubband absorption in a GaAs/AlGaAs quantum well usually happens between two two-dimensional (2D) electronic states. However for sufficiently low doping levels, the electrons can be entirely distributed on the silicon localized states. We demonstrate that depending on the temperature, absorption in such structures is dominated either by 2D quantum well ...

ON SIGNAL-TO-NOISE RATIO-ASSISTED CROSSTALK CHANNEL ESTIMATION IN DOWNSTREAM DSL SYSTEMS

  • Guenach M.
  • Louveaux J.
  • Maes J.
  • Peeters M.
  • Vandendorpe L.
  • Whiting P.

Downstream (DS) crosstalk channels of digital subscriber line systems can be estimated based on the reported signal-to-noise ratio (SNR). In the case of an already active victim line (VL) impacted by the joining of a new disturber line (DL), sending perturbing signals on the VL and reporting the SNRs allow ...

ROOM-TEMPERATURE CONTINUOUS-WAVE METAL GRATING DISTRIBUTED FEEDBACK QUANTUM CASCADE LASERS

  • Carras M.
  • Marcadet X.
  • Parillaud O.

We report on the design and elaboration of continuous wave (cw) distributed feedback quantum cascade lasers (QCLs) using a simple metal grating approach without epitaxial regrowth, neither for the grating nor for the thermal extraction. Room temperature cw single monomode QCLs with 30 dB side mode suppression ratio are demonstrated ...

CAPACITY OF CHANNELS WITH FREQUENCY-SELECTIVE AND TIME-SELECTIVE FADING

  • Caire G.
  • Shamai S.
  • Tulino A.

This paper finds the capacity of single-user discrete-time channels subject to both frequency-selective and time-selective fading, where the channel output is observed in additive Gaussian noise. A coherent model is assumed where the fading coefficients are known at the receiver. Capacity depends on the first-order distributions of the fading processes ...

A CORRELATION FOR THE DETECTION OF TIME AND FREQUENCY OFFSETS

  • Jeanclaude I
  • Purohit V
  • Wilford P.

A correlation is proposed for use to detect time and frequency offsets in a received signal in a digital transmission system. Applications include time and frequency synchronization in a single frequency network; pre-distortion for high power amplifiers in a transmitter. The correlation is formed with the products of two pairs ...

COEXISTENCE STUDIES FOR 3GPP LTE WITH OTHER MOBILE SYSTEMS

  • Tatesh S.

To ensure LTE systems can coexist with other mobile systems operating in the same geographical area, or the LTE Base Station (BS) can be collocated with other mobile system BSs, coexistence studies for LTE with other systems have been carried out in 3GPP. In this article, we provide an overview ...

EXPERIMENTAL AND THEORETICAL LINEARITY INVESTIGATION OF HIGH-POWER UNITRAVELING-CARRIER PHOTODIODES

  • Achouche M.
  • Carpentier D.
  • Chtioui M.
  • Enard A.
  • Lelarge F.
  • Rousseau B.

In this letter, the third-order intermodulation distortion of a high-power InGaAs-InP unitraveling-carrier photodiode is examined. Based on experimental data, we have developed an analytical model using a harmonic balance method. The response-time reduction, under high-current operation, is identified as the main nonlinear mechanism before saturation occurss. In addition, a linearity ...

DEMONSTRATION OF A TUNABLE MICROWAVE-PHOTONIC NOTCH FILTER USING LOW-LOSS SILICON RING RESONATORS

  • Beals M.
  • Beattie J.
  • Carothers D.
  • Gill D.
  • Kimerling L.
  • Kun-Yii T
  • Michel J.
  • Patel S.
  • Pomerene A.
  • Rasras M.
  • White A.
  • Young-Kai C

We present a fully tunable multistage narrowband optical pole-zero notch filter that is fabricated in a silicon complementary metal oxide semiconductor (CMOS) foundry. The filter allows for the reconfigurable and independent tuning of the center frequency, null depth, and bandwidth for one or more notches simultaneously. It is constructed using ...

LOW-CHIRP 85-GB/S DUOBINARY MODULATOR IN INP USING ELECTROABSORPTION MODULATORS

  • Adamiecki A.
  • Buhl L.
  • Doerr C.
  • Raybon G.
  • Sauer N.
  • Sinsky J.
  • Zhang L.

In 2005, Griffin showed that an InP phase-shift-keying/duobinary Mach-Zehnder interferometer (MZI) modulator could achieve good transmission performance at 10 Gb/s, despite modest residual amplitude modulation in the phase modulators in the MZI (ratio of real to imaginary part of index change was ~0.1). Here we show that even strong amplitude ...

TRUSTED PARTNERS CREATE OPTIONS FOR GROWTH

  • Ramirez J

Managed services help communication service providers address business transformation challenges and grow with next-generation services.

THICK ABSORPTION LAYER UNI-TRAVELING-CARRIER PHOTODIODES WITH HIGH RESPONSIVITY, HIGH SPEED, AND HIGH SATURATION POWER

  • Achouche M.
  • Bernard S.
  • Carpentier D.
  • Chtioui M.
  • Enard A.
  • Jany C.
  • Lelarge F.
  • Pommereau F.
  • Rousseau B.

High responsivity backside-illuminated uni-traveling-carrier photodiodes (PDs) with a 1.2-mum-thick p-doped absorption layer are demonstrated. The fabricated PDs achieve simultaneously high speed, high responsivity, and good linearity under high-power operation. The measured responsivity at 1.55 mum is larger than 0.83 A/W at low photocurrent and increases up to 1 A/W at ...

25.6-TB/S WDM TRANSMISSION OF POLARIZATION-MULTIPLEXED RZ-DQPSK SIGNALS

  • Burrows E.
  • Charlet G.
  • Doerr C.
  • Gnauck A.
  • Kawanishi T.
  • Tran P.
  • Winzer P.

We demonstrate record 25.6-Tb/s transmission over 240 km using 160 WDM channels on a 50-GHz grid in the C+L bands. Each channel contains two polarization-multiplexed 85.4-Gb/s RZ-DQPSK signals, yielding a spectral efficiency of 3.2b/s/Hz in each band.

TERABIT TRANSMISSION AT 42.7-GB/S ON 50-GHZ GRID USING HYBRID RZ-DQPSK AND NRZ-DBPSK FORMATS OVER 16TIMES80 KM SSMF SPANS AND 4 BANDWIDTH-MANAGED ROADMS

  • Buhl L.
  • Burrows E.
  • Chandrasekhar P
  • Doerr C.
  • Gnauck A.
  • Kilper D.

We demonstrate for the first time the use of asymmetric-bandwidth interleaver-based reconfigurable optical add-drop multiplexer (ROADM) to transmit 42.7-Gb/s channels on a 50-GHz grid. Differential binary phase shift keyed (DBPSK) format was used on the wide passband side and differential quadrature phase shift keyed (DQPSK) format was used on the ...

HIGH GAIN BANDWIDTH PRODUCT OVER 140-GHZ PLANAR JUNCTION ALINAS AVALANCHE PHOTODIODES

  • Achouche M.
  • Carpentier D.
  • Decobert J.
  • Lagay N.
  • Pommereau F.
  • Rouvie A.

This letter demonstrates a planar junction GalnAs-AlInAs avalanche photodiode using back-side illumination through thinned InP substrate covered with chemical vapor deposition SiNx antireflection coating. The combined properties of very low dark current (Idark(M = 0) = 17 nA), low excess noise factor (f(M = 10) = 3.5), and high gain ...

TEST OPTIMIZATION USING SOFTWARE VIRTUALIZATION

  • Krishnamurthy B.
  • Swaminathan S

The availability of testing infrastructure is a major factor in product development project costs. Software virtualization is a powerful mechanism for simulating a test setup on a few desktops that would otherwise require "real" equipment. It has shown a savings of about 30 percent of overall product development costs by ...

ENHANCED PHASE-SHIFTED PILOTS BASED CHANNEL ESTIMATION FOR MIMO-OFDM SYSTEMS WITH VIRTUAL SUBCARRIERS

  • Cai L
  • Li D.
  • Yang H.
  • Zhu X.

Generalizing a conventional phase-shifted pilot (PSP) sequences and discrete Fourier Transform (DFT) based channel estimator to MIMO-OFDM systems with virtual subcarriers, this paper presents two enhanced channel estimators applying Wiener interpolation and smoothing. Simulation results show that the proposed schemes can almost eliminate the mean square error floor of the ...