The power of the middle bit of a #P function

Peer Reviewe

Frontier Capital: Early Stage Investing for Financial Returns and Social Impact in Emerging Markets

This report outlines the importance and promise of serving low- and lower-middle-income (LMI) populations -- essentially, the groups situated between the very bottom of the pyramid and the existing middle class. As we detail herein, LMI populations have huge unmet needs and face quite a bit of instability -- challenges that can be addressed by innovative business models. We believe companies serving this demographic represent an under-tapped opportunity, both for financial returns and for outsized impact. The LMI segment represents a major market opportunity. For example, in Latin America and the Caribbean, the purchasing power of the LMI population is estimated at $405B. In South Asia, it is estimated at$483B

A transceiver module of the Mu radar

The transceiver (TR) module of a middle and upper atmospheric radar is described. The TR module used in the radar is mainly composed of two units: a mixer (MIX unit) and a power amplifier (PA unit). The former generates the RF wave for transmission and converts the received echo to the IF signal. A 41.5-MHz local signal fed to mixers passes through a digitally controlled 8-bit phase shifter which can change its value up to 1,000 times in a second, so that the MU radar has the ability to steer its antenna direction quickly and flexibly. The MIX unit also contains a buffer amplifier and a gate for the transmitting signal and preamplifier for the received one whose noise figure is less than 5 dB. The PA unit amplifies the RF signal supplied from the MIX unit up to 63.7 dBm (2350 W), and feeds it to the crossed Yagi antenna

A focal plane processor for continuous-time 1-D optical correlation applications

This chapter describes a 1-D Focal Plane Processor, which has been designed to run continuous-time optical correlation applications. The chip contains 200 sensory processing elements, which acquire light patterns through a 2mm ×10.9μm photodiode. The photogenerated current is scaled at the pixel level by five independent 3-bit programmable-gain current scaling blocks. The correlation patterns are defined as five sets of two hundred 3-bit numbers (from 0 to 7), which are provided to the chip through a standard I2C interface. Correlation outputs are provided in current form through 8-bit programmable gain amplifiers (PGA), whose configurations are also defined via I2C. The chip contains a mounting alignment help, which consists of three rows of 100 conventional active pixel sensors (APS) inserted at the top, middle and bottom part of the main photodiode array. The chip has been fabricated in a standard 0.35μm CMOS technology and its maximum power consumption is below 30mW. Experimental results demonstrate that the chip is able to process interference patterns moving at an equivalent frequency of 500kHz.Junta de Andalucía 2006-TIC-2352Ministerio de Ciencia e Innovación TEC2009-1181

Influence of ASE Noise on Performance of DWDM Networks Using Low-power Pumped Raman Amplifiers

We present the results of investigation  for  influence of amplified spontaneous emission (ASE) noise, noise figure (NF) and  chromatic dispersion on the performance of middle-distance Dense-wavelength-division-multiplexing (DWDM) networks using low-power pumped distributed Raman amplifiers (DRAs) in two different pump configurations, i.e., forward and backward pumping. We found that the pumping configurations, ASE noise, and dispersion play an important role for improving network performance by decrease of noise figure and bit error rate (BER) of the system. Simulation results show that the lowest bit error rate and low noise figure were obtained, when using forward pumping configuration. Moreover, we have also compared ASE noise powers of the simulation with these of the experiment. These results conclude that DRA with low pump power  ($1$~W) is the promising key technology for short-- and/or middle-distance DWDM transmission networks

Revisiting the RBLE design based on Matlab simulation

As a key low-power communication technique, backscatter communication has received significant attention since the rising of the Internet of Things (IoT). We revisit the state-of-the-art backscatter system, RBLE [1]. It solves several key reliability issues of backscatter system including unreliable two-step modulation, productive-data dependency, and lack of interference countermeasures. We implement a Matlab simulation version of this. It uses the reverse whiten technique to generate a single tone signal, operates direct frequency on it and calculates the bit error rate (BER) to evaluate. We give the spectrograms of the middle waveform results, compare the influence of different modulation methods and analyze the cause of high BER. In the end, we discuss the future prospects of the applications using RBLE.Comment: 6 pages, 14 figure

CMOS design of a current-mode multiplier/divider circuit with applications to fuzzy controllers

Multiplier and divider circuits are usually required in the fields of analog signal processing and parallel-computing neural or fuzzy systems. In particular, this paper focuses on the hardware implementation of fuzzy controllers, where the divider circuit is usually the bottleneck. Multiplier/divider circuits can be implemented with a combination of A/D-D/A converters. An efficient design based on current-mode data converters is presented herein. Continuous-time algorithmic converters are chosen to reduce the control circuitry and to obtain a modular design based on a cascade of bit cells. Several circuit structures to implement these cells are presented and discussed. The one that is selected enables a better trade-off speed/power than others previously reported in the literature while maintaining a low area occupation. The resulting multiplier/divider circuit offers a low voltage operation, provides the division result in both analog and digital formats, and it is suitable for applications of low or middle resolution (up to 9 bits) like applications to fuzzy controllers. The analysis is illustrated with Hspice simulations and experimental results from a CMOS multiplier/divider prototype with 5-bit resolution. Experimental results from a CMOS current-mode fuzzy controller chip that contains the proposed design are also included

Design And Development Of Remotely Pumped Erbium Doped Fiber Amplifier Transmission System

Erbium Doped Fiber Amplifier (EDFA) has been deployed extensively in optical communication systems especially for a long haul transmission link. Basically, EDFA requires a local pump laser for its optical amplification. This design will encounter problem if the amplifier is located at the middle of transmission line where power supply for the pump laser is unavailable. Therefore, remotely pumped amplifier can overcome the problem by injecting the pump light from either side of the transmission ends; transmitter or receiver. This dissertation reveals a new technique of designing a repeaterless transmission system using a remotely pumped EDFA. By varying the length of transmission fiber before and after EDFA, its location can be optimized for a specific pump power. A bit error rate is used as the main performance parameter and its threshold value is set at better than 10-10. The optimized location of EDFA will lead to the maximum transmission distance where it is found that the location of EDFA is closer to the receiver side.In conclusion, the EDFA location on transmission line using remotely pumped technique gives major impact to the system’s performance