Bit Error Rate Measurements Research Articles

Prototype experience for MIMO BLAST over third-generation wireless system

In this paper, a multiple-input-multiple-output (MIMO) extension for a third-generation (3G) wireless system is described. The integration of MIMO concepts within the existing UMTS standard and the associated space-time RAKE receiver are explained. An analysis is followed by a description of an actual experimental MIMO transmitter and receiver architecture, both realized on digital signal processors (DSPs) and FPGAs within a precommercial OneBTS base station. It uses four transmit and four receive antennas to achieve downlink data rates up to 1 Mb/s per user with a spreading factor of 32 and the UMTS chip rate of 3.84 MHz. Furthermore, different MIMO detectors are evaluated, comparing their performance and complexity. System performance is evaluated through simulations and indoor over-the-air measurements. Capacity and bit-error rate measurement results are presented.

A SiGe HBT IC CHIPSET for40-Gb/s OPTICAL TRANSMISSION SYSTEMS

Using a 0.2-μm self-aligned epitaxial-growth silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technology, we have developed a chipset for 40-Gb/s time-division multiplexing optical transmission systems. In this paper, we describe seven analog and digital ICs: a 45-GHz bandwidth transimpedance amplifier, a 48.7-GHz bandwidth automatic-gain-controllable amplifier, a 40-Gb/s decision circuit, a 40-Gb/s full-wave rectifier, a 40-Gb/s limiting amplifier with a 32-dB gain, a 45-Gb/s 1:4 demultiplexer, and a 45-Gb/s 4:1 multiplexer. To increase bandwidth of the transimpedance amplifier, a common-base input stage is introduced. In order to have high gain and wide bandwidth simultaneously, active load circuits composed of a differential transimpedance amplifier are used for the AGC amplifier, the limiting amplifier, and the decision circuit. Full-rate clocking is employed to reduce the influence caused by clock-duty variation in digital circuits such as the decision circuit, the demultiplexer, and the multiplexer. All ICs were characterized by using on-wafer probes, and some of them were built in brass-packages for bit-error rate measurement.

BER and power penalty fluctuations due to PMD statistics in 10 Gbit∕s optical transmissions

Polarisation-mode dispersion (PMD) in optical fibres causes a time-varying power penalty for the receiver. This variation has the same time-scale as low bit error rate (BER) measurements. Hereby, power penalty statistics can be difficult to determine with traditional BER measurements. A method where the statistics can be measured both quickly and accurately is proposed.

Spatial investigation of transverse mode turn-on dynamics in VCSELs

Data transmission experiments with single-mode as well as multimode 850-nm vertical-cavity surface-emitting lasers (VCSELs) are carried out from a near-field point of view. Special attention is paid to important quantities like on/off-ratio and bit error rate (BER). A single-mode VCSEL oscillating on the fundamental LP/sub 01/ mode shows no change in eye opening, on/off-ratio, and BER at different lateral fiber coupling positions. In the case of a multimode VCSEL oscillating both on the LP/sub 01/ mode and LP/sub 11/ donut mode, we observe a significant lateral change in the on/off-ratio, which plays an important role in BER measurements.

Optical millimeter-wave generation and wireless data transmission using a dual-mode laser

A dual-mode self-pulsating laser is presented as a transmitter source for millimeter wave generation in an experimental hybrid fiber radio system. The performance is evaluated by bit-error rate measurements in the 40-GHz-frequency range including a radio link and a fiber based transmission with lengths up to 60 km.

Optoelectronic generation and modulation of millimeter waves in a single InP-GaInAs photo heterojunction bipolar transistor

We demonstrate the use of an InP-GaInAs photo heterojunction bipolar transistor as a millimeter wave transducer. A 45-GHz carrier signal is generated by mixing two optical signals impinging on the optical port at the base. Simultaneously, the base electrode is fed by an electrical signal which modulates the 45 GHz carrier. Analog modulation capabilities were characterized in terms of the modulation depth and linearity while digital modulation was evaluated by a measurement of bit error rates.

Coherent-to-incoherent light conversion for optical correlators

The authors present a novel coherent-to amplified spontaneous emission (ASE) converter based on SOA's cross-gain modulation (XGM) in a counterpropagating configuration. Experimental characterizations of the ASE converter with bit-error rate (BER) measurements at 2.5 and 5 Gb/s are shown. The device capabilities are exploited in a delay lines optical recognizer at 2.5 Gb/s. Recognition is based on a coherent-to-incoherent light conversion followed by a fiber array correlation filter. Experimental evidence here reported shows performance improvement in comparison with a scheme which adopts a standard telecom source.

5-Gbit/s BER performance on an all fiber-optic add/drop device based on a taper-resonator-taper structure

We present an all fiber-optic add/drop device based on a taper-resonator-taper structure with improved characteristics. Several gigahertz bandwidths are observed using microspheres having diameters ranging from 30 to 50 /spl mu/m. Extinction ratios as high as 26 dB of the dropped channel are obtained due to nearly ideal coupling and phase matching between the fiber tapers and the small resonator. This is the first time that bit-error rate (BER) measurements have been performed on such couplers. For a device with an optical bandwidth of 3.8 GHz, the BER shows less than 2-dB penalty at 5 Gbit/s and no signs of an error floor.

Polarization- and interval-independent wavelength conversion at 2.5 Gb/s by means of bidirectional four-wave mixing in semiconductor optical amplifiers

We report interval-polarization-independent wavelength conversion at 2.5 Gb/s using four-wave mixing in a single semiconductor optical amplifier. These results have been obtained with a dual-pump configuration in a bidirectional geometry. Bit-error-rate (BER) curves are reported for a conversion shifts of -1 and +1 THz. The signal polarization was automatically scrambled during the BER measurement. The penalty with respect to the back-to-back line is 2.4 and 1.6 dB, respectively.

Bit-error-rate performance dependence on pump and signal powers of the wavelength converter based on FWM in semiconductor optical amplifiers

The influence of input pump and signal powers on the converted optical signal-to-noise ratio (OSNR), intersymbol interference (ISI), and bit-error-rate (BER) performance of the wavelength converter based on four-wave mixing (FWM) in semiconductor optical amplifiers is presented. The results of BER measurement show that there exists a tradeoff between maximizing OSNR and minimizing ISI. The minimum power penalty less than 1 dB is obtained by optimizing the input pump and signal powers.

Pulse jitter and timing errors in RSFQ circuits

We have carried out measurements of bit error rate (BER) of Rapid Single-Flux-Quantum (RSFQ) XOR gates with various nominal dc power supply voltages (from 0.1 V to 1.0 mV), operating at speeds up to 25 GHz. (For these gates, implemented using HYPRES' standard, 3.5-/spl mu/m, 10 /spl mu/A//spl mu/m/sup 2/ Nb-trilayer process, this speed is close to maximum.) A special on-chip RSFQ test circuit allowed high-speed measurements of BER in the range from 10/sup -9/ to 10/sup -13/ to be carried out. As a result of these experiments, a new type of thermal-fluctuation-induced digital errors in RSFQ circuits has been identified. These errors arise at high speed due to time jitter of data and clock pulses. We have developed a simple theory of these errors which allows a fair description of the experimental data. The theory shows that in some cases the timing errors may be an important factor limiting speed performance of RSFQ circuitry. Nevertheless, our XOR gates could operate at 25 GHz with BER below 10/sup -13/ at the standard temperature (4.2 K) at any dc power supply voltage in our range. For the lowest voltage (0.1 Volt) the calculated static power dissipation in the gate was as low as 23 nanowatts, lower than the unavoidable dynamic dissipation (43 nanowatts).

Measurements of BER performance for bipolar encoding of an SFS

This paper reports on the measurements of bit error rate (BER) performance for a broad-band optical communications scheme that encodes the power spectrum of an erbium-doped superfluorescent fiber source (SFS) with bipolar equivalent codes. The proposed scheme, like spectrum-sliced wavelength division multiplexing (WDM), suffers from the excess noise associated with the detection of a thermal-like source. BER calculations based on measured testbed characteristics and a simple model are compared with BER measurements for one and two active users. In addition, the performance of a single user in the presence of broad-band spectral interference is investigated, giving a preliminary estimate of multiuser capacity. This paper discusses various solutions for increasing network capacity and performance, relevant to the proposed scheme as well as to wavelength division multiplexing (WDM).

Detection of errors recovered by decoders for signal quality estimation on rain-faded AWGN satellite channels

We describe a method for estimating satellite link quality for use with rain fade countermeasures. The method applies to convolutionally encoded bit streams. It is based on the measurement of the uncoded data bit-error rate (BER) which is estimated by monitoring the errors recovered by a Viterbi decoder. Using a previously developed attenuation model, the measurement time intervals are optimized for a simple application, and the performance of the estimator is shown.

Measurement and estimation of BER degradation of PHS due to electromagnetic disturbances from microwave ovens

Microwave ovens operating in 2.45 GHz band emit broad band noise that may interfere with digital mobile communication systems above 1 GHz. We therefore measured the bit error rate (BER) degradation of a typical personal handy-phone system (PHS) receiver due to the electromagnetic disturbances emitted from two types of ovens, five measurements in all, located 0.5, 1, and 3 m from the receiver. BER degradation over 10−3 was not observed from conventional transformer-type microwave ovens even at 0.5 m. Switching type ovens, such as are mainly used in Japan, generally radiate higher level disturbances than conventional ovens and an oven of this kind degraded the BER characteristics by more than 10−2 at 3 m. A noise waveform analyzer was developed to measure statistical parameters of the noise envelope such as the amplitude probability distribution (APD) and crossing rate distribution. APD of the noise envelope emitted from ovens was measured in the 1.9 GHz frequency band which is assigned for PHS. BER degradation of a PHS receiver by the disturbance of the ovens was also measured simultaneously with the APD measurement. Good correlation is found between BER and APD measurement results. An estimation method for BER from the APD measurement data is proposed and its applicability evaluated. © 1998 Scripta Technica. Electron Comm Jpn Pt 1, 81(2): 55–63, 1998

Using additive white binary noise to marginalize read channels

Optimization of bit error rate (BER) is typically not a part of disk drive burn-in, due to the large amount of time required to measure bit error rates accurately. In this paper, theoretical calculations, numerical simulations, and experimental results are used to show that additive white binary noise can be used to marginalize the performance of a read channel. As measurements of the larger BERs due to marginalization are much faster than normal BER measurements, this technique makes practical the use of BER based optimization during drive burn-in.

Design of equalized maximum-likelihood receiver

A receiver structure referred to as equalized maximum likelihood (EML) is proposed to reduce the complexity of the maximum-likelihood sequence detector (MLSD). Performance of EML is evaluated through the bit-error rate (BER) measurement for a magnetic recording channel. EML exhibits 1-dB gain over the conventional partial response maximum likelihood (PRML) for 10/sup -5/ BER.

1-Gb/s modulation characteristics of a vertical-cavity surface-emitting laser array module

Vertical-cavity surface-emitting lasers (VCSELs) are promising devices for low-cost optical data communications. We fabricated an 8-channel VCSEL array module that is easily push/pull-connected to a mechanically transferable (MT) fiber connector. Modal noise had little adverse effect on bit-error-rate (BER) performance. A BER measurement of 8-channel VCSELs recorded a sensitivity of less than -23.7 dBm at 1 Gb/s and BER=10/sup -11/.

A mobile broad-band communication system based on mode-locked lasers

A concept is proposed for a pico-cellular network for broad-band mobile communication on a millimeter-wave basis. How microwave optical-signal-processing techniques based on mode-locked lasers (MLLs), optical modulators, and high-speed photo diodes (PD's) can advantageously be applied in the optical feeder lines of a pico-cellular network at 60 GHz is investigated. The external cavity MLL (at 81.25 GHz) used for the experiments showed a single-sideband (SSB) phase noise of -59 dBc/Hz at 100-Hz offset, when actively locked at 6.25 GHz. With the PD, and limited by the V-band mixer equipment, spectral harmonics up to 100 GHz could be detected. For the downlink configuration, a 400-MHz subcarrier is modulated with a 155-Mb/s data signal and upconverted to 62.9 GHz using an MLL and a fast PD. The upconverted sideband at 62.9 GHz was received with an optical power of -14.3-dBm at a bit-error-rate (BER) equal to 10/sup -9/ without any additional penalty due to transmitting the signal over 3 km of optical fiber. BER measurements at 155 Mb/s down to 10/sup -11/ were made. For the uplink, the digitally encoded RF signal is downconverted also by optical microwave signal processing. A 155-Mb/s data encoded 19.21-GHz signal is downconverted to 460 MHz using a mode-locked laser, an optical modulator, and a 600-MHz optical receiver front end. A receiver sensitivity of -24.5 dBm (BER equal to 10/sup -9/) is demonstrated with the microwave signal being transmitted over a 1-m radio link and 3 km of optical fiber.

High temperature superconducting resonators and switches: design, fabrication, and characterization

We report our recent efforts in designs of several RF and microwave devices using high temperature superconducting (HTS) thin film technology. Devices considered include transmission lines, resonators, switches, and phase shifters in microstrip, stripline and coplanar waveguide. The circuit design, modeling, simulation, fabrication, packaging, and testing are discussed. Using a two-dimensional (2-D) EM simulator, we have optimized the geometry of the RF microstrip and stripline resonators for frequencies near 900 MHz. An unloaded Q is obtained as high as 80,000, three orders of magnitude greater than the traditional 2-D gold or copper resonators with identical structures. On-wafer probe and bit-error rate measurements show that the HTS transmission lines have an extremely small insertion loss and dispersion; thus they are ideal candidates for applications in multichip module interconnects and delay lines. A sharp switching characteristic and an unusually strong RF power hysteresis loop have been observed in the HTS lines. This interesting behavior has been utilized for designs of new HTS microwave phase shifters. The use of HTS lines can substantially reduce the losses suffered by conventional PIN diode switches.

All-optical 1300-nm to 1550-nm wavelength conversion using cross-phase modulation in a semiconductor optical amplifier

All-optical 1300-nm to 1550-nm wavelength converters may be important components in lightwave networks which use both the 1300-nm and the 1550-nm low-loss transmission windows of silica optical fiber. We describe a new all-optical 1300-nm to 1550-nm wavelength converter, based on cross-phase modulation in a 1300-nm semiconductor optical amplifier. We demonstrate operation of the wavelength converter at 1.25 Gb/s, and present bit-error rate measurements. The wavelength converter demonstrated here potentially operates at high speed, with low input power and low polarization-sensitivity.