Sumit Jamuar: Indians are 20 of the world's population, but represent only 1 of existing genetic data

As the new frontier in medicine, genomics brings with it the hope of allowing researchers to find the cure for a number of largely incurable diseases, from cancer to Alzheimer’s, to infectious diseases and beyond. The challenge now is to map the DNA of as many ethnicities and nationalities as possible. Currently, 81 per cent of the existing genetic data is from Caucasians. One company is trying to bridge the gap by analysing the genome of different ethnicities in India, with hopes of expanding to the rest of Asia, Latin America and Africa. “You look at India, with 1.3 billion people, 20 per cent of the world’s population. A lot of people of Indian ethnicities reside globally, and yet they comprise less than 1 per cent of genomic insights and understanding”, says Sumit Jamuar, chairman and CEO of Global Gene Corp. He spoke with LSE Business Review’s managing editor, Helena Vieira, on 9 November 2017, during Web Summit in Lisbon

Adaptive spatial mode of space-time and spacefrequency OFDM system over fading channels

In this paper we present a 2 transmit 1 receive (1 Tx : 1 Rx) adaptive spatial mode (ASM) of space-time (ST) and space-frequency (SF) orthogonal frequency division multiplexing (OFDM). At low signal to noise ratio (SNR) we employ ST-OFDM and switch to SF-OFDM at a certain SNR threshold. We determine this threshold from the intersection of individual performance curves. Results show a gain of 9 dB (at a bit error rate of 10-3) is achieved by employing adaptive spatial mode compared to a fixed ST-OFDM, almost 6 dB to fixed SF-OFDM, 4 dB to Coded ST-OFDM and 2 dB to a fixed coded SF-OFDM, at a delay spread of 700 ns

Design of analog mixer for RF front-end

This paper presents design of analog mixer using modified Gilbert cell topology for use in RF front. The proposed circuit gives improvement in its performance. The input RF and LO frequency is set to 2500MHz and 2250MHz respectively, resulting in an output IF frequency of 250MHz.The simulation results show that the conversion gain is 9.605dB, single-sideband noise figure is 9.448dB and output IM3 intercept point is 15.764dBm with power consumption of 24.732mW. It uses supply voltage of 1.8V and the circuit layout has been obtained using CMOS 0.18μm technology fabrication

Analysis of transmit-receive diversity in Rayleigh fading

We analyze the error performance of a wireless communication system employing transmit-receive diversity in Rayleigh fading. By focusing on the complex Gaussian statistics of the independent and identically distributed entries of the channel matrix, we derive a formula for the characteristic function (c.f.) of the maximum output signal-to-noise ratio. We use this c.f. to obtain a closed-form expression of the symbol error probability (SEP) for coherent binary keying. The method is easily extended to obtain the SEP for the coherent reception of M-ary modulation schemes

A low power 2.4 GHz variable-gain low noise amplifier for wireless applications

A 2.4 GHz variable-gain low noise amplifier (VGLNA) intended for use in a Wide-band Code Division Multiple Access receiver was designed in 0.18 um CMOS process for low voltage and low power applications. Rivaling classical designs using voltage mode approach, this design used the current mode approach, utilizing the current mirror principle to obtain a controllable gain range from 8.26 dB to 16.95 dB with good input and output return losses. By varying the current through the widths of transistors and a bias resistor, the VGLNA was capable of exhibiting 8 dB gain tuning range without degrading the noise figure. Therefore, higher gain was possible at lower current and thus at lower power consumption. Total power consumption simulated was 4.63 mW from a 1 V supply and this gave a gain/power quotient of 3.66 dB/mW. Comparing this with available published data, it was observed that this work demonstrated a good gain tuning range and the lowest noise figure with such power consumption

An improved power consumption circuit of a 5.7 GHz variable-gain low noise amplifier (VGLNA) for RF applications

A low voltage topology that uses a capacitively coupled resonating element has been introduced using 0.18 mum CMOS technology. The topology utilizes the decoupling scheme to dc isolate circuit elements that are connected in series and share a common dc current. A 5.7 GHz variable-gain low noise amplifier (VGLNA) is presented with simulation results exhibiting a noise figure of 1.02 dB, power gain of 19.41 dB with gain tuning range of 6 dB and IIP3 of -1.11 dBm. The power consumption reported is 12.88 mW at supply of Vdd = 0.7 V for power optimization circuit. Simulation results show that the proposed VGLNA has better noise performance and improved power consumption compared to the conventional cascode VGLNA

A full rate concatenated space-frequency and space-time OFDM over Naftali fading channels

In this paper we investigate 2 transmit and 1 receive (2Tx:1Rx) space-frequency orthogonal frequency division multiplexing (SF-OFDM) and space-time OFDM (ST-OFDM) concatenated with convolutional channel coding as a redundancy method to combat channel impairments. We built our SF and ST-OFDM on top of our coded OFDM (COFDM) with coding rate of 1/4 and constraint length of 10. We simulate our concatenated SF-OFDM and ST-OFDM over a multipath fading channel using Naftali 802.11 channel model under different delay spreads in relation to outdoor environment. Concatenated SF- OFDM performs slightly better than ST-OFDM at delay spread of 2.0 microseconds, but both are almost comparable at all other delay spreads. These two schemes outperforms other schemes such as single antenna coded OFDM and Alamouti's Space-Time Block Code (STBC) under these conditions by as much as 10 dB at BER of 104

A simplified sphere decoding algorithm for MIMO transmission system

In sphere decoding the choice of sphere radius is crucial to excellent performance. In Chan-Lee sphere decoding -based algorithm, the problem of choosing initial radius has been solved by making the radius sufficiently large, thus increasing the size of the search region. In this paper we present maximum likelihood decoding using simplified sphere decoder as apposed to the original sphere decoder for the detection of cubic structure quadrature amplitude modulation symbols. This simple algorithm based on Chan-Lee sphere decoder allows the search for closest lattice point in a reduced complexity manner compared to original sphere decoder for multiple input multiple output system with perfect channel state information at the receiver. Results show symbol error rate has stabilized even at very low initial value of the square radius