Receiver Sensitivity Measurements Research Articles

Study of an Evaluation Model for AIS Receiver Sensitivity Measurements

To guarantee that ships can navigate safely, the International Maritime Organization mandates that all ships navigating internationally must install the automatic identification system (AIS). AIS works in the very high-frequency (VHF) maritime mobile band, and to ensure the signal receiving performance of AIS equipment, it is necessary that the receiver sensitivity can be quickly evaluated and detected. Hence, we propose an evaluation model of AIS receiver sensitivity. The model first measures the packet error rate (PER) of AIS data transmission at a specific power. The distribution of the AIS receiver sensitivity characteristic curve under any transmitted power can be directly obtained, and then whether or not the sensitivity of the AIS receiver satisfies the performance requirements can be quickly evaluated. Regression analysis and the results of actual measurement demonstrate that this model has a goodness of fit (R-squared) value of 0.99 between the power–PER curve of the analog input signal and the measured data, which signifies test efficiency and accuracy beyond conventional test methods.

Data-Driven Measurement of Receiver Sensitivity in Wireless Communication Systems

Receiver sensitivity is one of the most important parameters in determining the overall performance of a radio frequency communication system. The traditional receiver sensitivity measurement is to use exhaustive search in a specified range to identify the receiver's sensitivity. However, such an exhaustive search is neither efficient in terms of measurement time, nor accurate due to the fixed step-size. In this paper, a data-driven approach is proposed to measure the receiver sensitivity based on a dynamic linearization representation of a time-varying pseudo-gradient parameter estimation procedure. Unlike the model-based approach, the proposed data-driven approach is dependent only on the input and output measurement data. Furthermore, an analytical approach is presented to derive the minimum number of test packets needed to satisfy the desired confidence level for packet error rate estimation. By adapting the number of test packets, the proposed approach can converge to the exact receiver sensitivity with less time. A theoretical analysis of the proposed approach is provided and further validated by numerical analyses and real-world experimental verification. These analyses show that the proposed data-driven sensitivity measurement can a achieve good estimation performance within a few iterations as well as reduce measurement time.

High-gain erbium-doped fiber amplifier incorporating a double-pass amplification technique as a preamplifier

We present a high-gain erbium-doped fiber amplifier to be utilized as a preamplifier. A double-pass amplification technique is used in the first-stage amplifier together with a tunable bandpass filter. The secondstage amplifier is a counter-pumped configuration and another tunable bandpass filter is utilized to filter out amplified spontaneous emission from the first-stage amplifier. This design is able to produce a high gain of 55.6 dB and a noise figure of 6.02 dB at 1530 nm with a signal power of −45 dBm. The receiver sensitivity measurement shows that the proposed amplifier improves the minimum detectable power from −33.7 to −40.8 dBm for a bit-error rate of 10−11 at 155 Mbps.

High-gain erbium-doped fiber amplifier incorporating a double-pass amplification technique as a preamplifier

We present a high-gain erbium-doped fiber amplifier to be utilized as a preamplifier. A double-pass amplification technique is used in the first-stage amplifier together with a tunable bandpass filter. The secondstage amplifier is a counter-pumped configuration and another tunable bandpass filter is utilized to filter out amplified spontaneous emission from the first-stage amplifier. This design is able to produce a high gain of 55.6 dB and a noise figure of 6.02 dB at 1530 nm with a signal power of −45 dBm. The receiver sensitivity measurement shows that the proposed amplifier improves the minimum detectable power from −33.7 to −40.8 dBm for a bit-error rate of 10−11 at 155 Mbps.

A high-performance optical receiver for 622 Mb/s direct-detection systems

A report is presented on the measurement of receiver sensitivity and noise characteristics of a high-performance optical receiver using a low-noise InGaAs avalanche photodiode (APD) and a low-noise high-electron mobility transistor (HEMT). At a bit rate of 622.08 Mb/s and a wavelength of 1.297 mu m, the measured receiver sensitivity is -48.3 dBm. This is equivalent to a sensitivity of 155 photons/b and is about 12 dB away from the quantum limit of 10 photons/b. >

Objective measurement of receiver sensitivity

The sensitivity of radar receivers is checked with a pulsed radio frequency signal which is adjusted until the observed magnitude is distinguishable from the background noise level as displayed on an oscilloscope. Because of the noisy nature of the display the results are highly subjective, but by eliminating the idiosyncratic element, a calibration instrument has been designed to give a rapid and accurate presentation to the operator.

Characteristics of a semiconductor laser pumped brillouin amplifier with electronically controlled bandwidth

We demonstrate the operation of a semiconductor laser pumped fiber Brillouin amplifier. An optical gain of 5.5 dB/mW of pump power is obtained. The 15-MHz intrinsic bandwidth of the amplifier was extended more than one order of magnitude by adding frequency modulation to the pump laser. Bit-error-rate receiver sensitivity measurements with an in-line Brillouin amplifier demonstrate a 16-dB improvement in the system gain at 10 Mbit/s and a 8.5-dB improvement at 90 Mbit/s. Noise calculations show that the amplifier has an excess noise factor of 50-500 depending on the amplifier length and pump power.

Performance characteristics of 1.5-µm external cavity semiconductor lasers for coherent optical communication

The performance characteristics of 1.5-μm external cavity semiconductor lasers have been investigated. Measurements of phase, frequency, and amplitude stability are presented together with the power and threshold characteristics. Amplitude shift keyed coherent receiver sensitivity measurements gave a receiver sensitivity of -55.7 dBm at 150 Mbit/s equivalent to 137 photon/bit as compared to previous amplitude shift keying results of 520 photon/bit and the shot-noise limit of 36 photon/bit.

ASK heterodyne receiver sensitivity measurements with two in-line 1.5 μm optical amplifiers

A heterodyne amplitude shift keying configuration was used to evaluate the performance of resonant-type optical amplifiers in a coherent lightwave communication system. With two in-line amplifiers, each with a gain of 25 dB, the total loss between the transmitter and the receiver was 95 dB at 10-9 bit error rate. At a 100 Mbit/s data rate, the receiver sensitivity without amplifiers was -49.3 dBm. With two amplifiers the receiver sensitivity could be maintained at -49.0 dBm.

New low dark current, high speed Al0.48In0.52As/ Ga0.47In0.53As avalanche photodiode by molecular beam epitaxy for long wavelength fiber optic communication systems

We report a new Al0.48In0.52As/Ga0.47In0.53As avalanche photodiode with separate absorption and multiplication regions (SAM APD) and an undoped spacer layer in the gain region. These devices grown by molecular beam epitaxy, have very low dark currents (4 nA at the onset of gain) which compare favorably with state-of-the-art InP/Ga0.47In0.53As SAM APD’s. Avalanche gains ≊60 and a high speed of response with a gain-bandwidth product ≊10 GHz are demonstrated. Receiver sensitivity measurements at 420 Mb/s and λ=1.3 μm with a Si bipolar transistor preamplifier yielded −36.0 dBm at a 10−9 bit error rate.

PSK homodyne receiver sensitivity measurements at 1.5 μm

Measurements of the receiver sensitivity for an experimental optical PSK homodyne system, operating at 140 Mbit/s and at a wavelength of 1.52 μm, have given a 19 dB sensitivity improvement over direct detection, and at −64 dBm is approximately 2 dB away from the theoretically predicted value.

Excess-noise and receiver sensitivity measurements of In 0.53 Ga 0.47 As/InP avalanche photodiodes

We report the results of excess-noise and normalised receiver sensitivity measurements for In0.53Ga0.47As/InP avalanche photodiodes for use in the λ=0.95 μm to 1.65 μm spectral region. The excess-noise measurements are consistent with a hole-to-electron ionisation rate ratio in InP of ∼ 0.4. The receiver sensitivity, measured at 45 Mbit/s and 10−9 bit-error-rate, was −53.2 dBm at a gain of 20 assuming unity quantum efficiency for the detector. This sensitivity is the highest reported at λ=1.3 μm and represents an improvement over a PIN detector using the same amplifier.

A Family of Air Traffic Control Radars

Some 20 years of activity in the field of air traffic control (ATC) radars is described. This activity includes the production of over 100 equipments installed in 20 countries all over the world and is a relevant technical contribution to provision of reliable surveillance of scheduled air carriers and general aviation. Three generations of equipment have been produced in this series: conventional design, solid state, and adaptive. The technical experience gained in evaluating the performance of ATC radars installed throughout the world is described in terms of target visibility in the clear, a ground clutter, and in adverse metrorological conditions. The estimation of radar coverage in the clear is derived from direct measurement of receiver sensitivity in terms of Pd and Pfa, while flight tests are utilized to verify actual performance in a given operational environment. A criterion to determine the significance of a flight test is described. In the effort to establish a reliable method of measurement, the subclutter visibility over ground clutter is related to the linear dynamic range of the moving-target indicator (MTI) receiver and to the improvement factor. The results obtained for the ATCR-22 adaptive radar line are described. Block diagrams and descriptions of the third generation radar equipment are given.

Specification and Measurement of Receiver Sensitivity at the Higher Frequencies

The paper discusses the influence of receiver noise on sensitivity performance at higher frequencies. Established I.R.E. standard definitions and test methods do not give proper emphasis to the important factor of noise. A practice recently adopted of specifying sensitivity in terms of noise figure is reviewed, and there is introduced a method, not yet commonly used, of measuring this quantity with a diode noise generator. Noise figure, however, is not an adequate specification of sensitivity, for it ignores over-all gain. To include both factors, a proposed combined sensitivity figure is presented. The alternatives for specifying sensitivity in terms of voltage or power are compared, and the concept of available power is explained.