Marvell Technology Group

About: Marvell Technology Group is a company organization based out in Tel Aviv, Israel. It is known for research contribution in the topics: Signal & Communication channel. The organization has 937 authors who have published 1302 publications receiving 18178 citations.

Capacity scaling laws in MIMO relay networks

Abstract: The use of multiple antennas at both ends of a wireless link, popularly known as multiple-input multiple-output (MIMO) wireless, has been shown to offer significant improvements in spectral efficiency and link reliability through spatial multiplexing and space-time coding, respectively. This paper demonstrates that similar performance gains can be obtained in wireless relay networks employing terminals with MIMO capability. We consider a setup where a designated source terminal communicates with a designated destination terminal, both equipped with M antennas, assisted by K single-antenna or multiple-antenna relay terminals using a half-duplex protocol. Assuming perfect channel state information (CSI) at the destination and the relay terminals and no CSI at the source, we show that the corresponding network capacity scales as C = (M/2) log(K) + O(1) for fixed M, arbitrary (but fixed) number of (transmit and receive) antennas N at each of the relay terminals, and K rarr infin. We propose a protocol that assigns each relay terminal to one of the multiplexed data streams forwarded in a "doubly coherent" fashion (through matched filtering) to the destination terminal. It is shown that this protocol achieves the cut-set upper bound on network capacity for fixed M and K rarr infin (up to an O(1)-term) by employing independent stream decoding at the destination terminal. Our protocol performs inter-stream interference cancellation in a completely decentralized fashion, thereby orthogonalizing the effective MIMO channel between source and destination terminals. Finally, we discuss the case where the relay terminals do not have CSI and show that simple amplify-and-forward relaying, asymptotically in K, for fixed M and fixed N ges 1, turns the relay network into a point-to-point MIMO link with high-SNR capacity C = (M/2) log(SNR) + O(1), demonstrating that the use of relays as active scatterers can recover spatial multiplexing gain in poor scattering environments

Noise Analysis of Regenerative Comparators for Reconfigurable ADC Architectures

Abstract: The need for highly integrable and programmable analog-to-digital converters (ADCs) is pushing towards the use of dynamic regenerative comparators to maximize speed, power efficiency and reconfigurability. Comparator thermal noise is, however, a limiting factor for the achievable resolution of several ADC architectures with scaled supply voltages. While mismatch in these comparators can be compensated for by calibration, noise can irreparably hinder performance and is less straightforward to be accounted for at design time. This paper presents a method to estimate the input referred noise in fully dynamic regenerative comparators leveraging a reference architecture. A time-domain analysis is proposed that accounts for the time varying nature of the circuit exploiting some basic results from the solution of stochastic differential equations. The resulting symbolic expressions allow focusing designers' attention on the most influential noise contributors. Analysis results are validated by comparison with electrical simulations and measurement results from two ADC prototypes based on the reference comparator architecture, implemented in 0.18-mum and 90-nm CMOS technologies.

Logical bridging system and method

Abstract: A system and method of extending a standard bridge to enable execution of logical bridging functionality are disclosed. In some implementations, a logical bridge may assign source logical port information to a data packet based on characteristics of the data packet, employ the source logical port information to learn the source address and to forward the data packet to a logical egress port, and map the logical egress port to a physical egress port at which the data packet is to be egressed. A tunnel interface may optionally be applied to a data packet upon egress.

A Low-Power, Linearized, Ultra-Wideband LNA Design Technique

Abstract: This work proposes a practical linearization technique for high-frequency wideband applications using an active nonlinear resistor, and analyzes its performance with Volterra series. The linearization technique is applied to an ultra-wideband (UWB) cascode common gate Low Noise Amplifier (CG-LNA), and two additional reference designs are implemented to evaluate the linearization technique - a standard (without linearization) cascode CG-LNA and a single-transistor CG-LNA. The single-transistor CG-LNA achieves +6.5 to +9.5 dBm IIP3, 10 dB (max.) gain, and 2.9 dB (min.) NF over a 3-11 GHz bandwidth (BW); the LNA consumes 2.4 mW from a 1.3 V supply. The cascode linearized LNA achieves +11.7 to +14.1 dBm IIP3, 11.6 dB (max.) gain, and 3.6 dB (min.) NF over 1.5 to 8.1 GHz; the cascode LNA consumes 2.62 mW from a 1.3 V supply. Experimental results show that the linearization technique improves the cascode LNA's IIP3 by a factor of 3.5 to 9 dB over a 2.5-10 GHz frequency range.

A Hybrid FMCW-Interferometry Radar for Indoor Precise Positioning and Versatile Life Activity Monitoring

Abstract: This paper presents a hybrid radar system that incorporates a linear frequency-modulated continuous-wave (FMCW) mode and an interferometry mode for indoor human localization and life activity monitoring applications. The unique operating principle and signal processing method allow the radar to work at two different modes for different purposes. The FMCW mode is responsible for range detection while the interferometry mode is responsible for life activities (respiration, heart beat, body motion, and gesture) monitoring. Such cooperation is built on each mode's own strength. Beam scanning is employed to determine azimuth information, which enables the system to plot 360° 2-D maps on which the room layout and objects' location can be clearly identified. Additionally, the transmitted chirp signal is coherent in phase, which is very sensitive to physiological motion and allows the proposed technique to distinguish human from nearby stationary clutters even when the human subjects are sitting still. Hence, the proposed radar is able to continuously track the location of individuals and monitor their life activities regardless of the complex indoor environment. A series of experiments have been carried out to demonstrate the proposed versatile life activity monitoring system.