An Energy-Efficient Reconfigurable Circuit Switched Network-on-Chip

Network-on-Chip (NoC) is an energy-efficient on-chip communication architecture for multi-tile System-on-Chip (SoC) architectures. The SoC architecture, including its run-time software, can replace inflexible ASICs for future ambient systems. These ambient systems have to be flexible as well as energy-efficient. To find an energy-efficient solution for the communication network we analyze three wireless applications. Based on their communication requirements we observe that revisiting of the circuit switching techniques is beneficial. In this paper we propose a new energy-efficient reconfigurable circuit-switched Network-on-Chip. By physically separating the concurrent data streams we reduce the overall energy consumption. The circuit-switched router has been synthesized and analyzed for its power consumption in 0.13 ¿m technology. A 5-port circuit-switched router has an area of 0.05 mm2 and runs at 1075 MHz. The proposed architecture consumes 3.5 times less energy compared to its packet-switched equivalen

High-Level Design Space and Flexibility Exploration for Adaptive, Energy-Efficient WCDMA Channel Estimation Architectures

Due to the fast changing wireless communication standards coupled with strict performance constraints, the demand for flexible yet high-performance architectures is increasing. To tackle the flexibility requirement, software-defined radio (SDR) is emerging as an obvious solution, where the underlying hardware implementation is tuned via software layers to the varied standards depending on power-performance and quality requirements leading to adaptable, cognitive radio. In this paper, we conduct a case study for representatives of two complexity classes of WCDMA channel estimation algorithms and explore the effect of flexibility on energy efficiency using different implementation options. Furthermore, we propose new design guidelines for both highly specialized architectures and highly flexible architectures using high-level synthesis, to enable the required performance and flexibility to support multiple applications. Our experiments with various design points show that the resulting architectures meet the performance constraints of WCDMA and a wide range of options are offered for tuning such architectures depending on power/performance/area constraints of SDR

Reconfigurable Turbo/Viterbi Channel Decoder in the Coarse-Grained Montium Architecture

Mobile wireless communication systems become multi-mode systems. These future mobile systems employ multiple wireless communication standards, which are different by means of algorithms that are used to implement the baseband processing and the channel decoding. Efficient implementation of multiple wireless standards in mobile terminals requires energy-efficient and flexible hardware. We propose to implement both the baseband processing and channel decoding in a heterogeneous reconfigurable system-on-chip. The system-on-chip contains many processing elements of different granularities, which includes our coarse-grained reconfigurable MONTIUM architecture. We already showed the feasibility to implement the baseband processing of OFDM and WCDMA based communication systems in the MONTIUM. In this paper we implemented two kinds of channel decoders in the same MONTIUM architecture: Viterbi and Turbo decoding

Radio-Communications Architectures

Wireless communications, i.e. radio-communications, are widely used for our different daily needs. Examples are numerous and standard names like BLUETOOTH, WiFI, WiMAX, UMTS, GSM and, more recently, LTE are well-known [Baudoin et al. 2007]. General applications in the RFID or UWB contexts are the subject of many papers. This chapter presents radio-frequency (RF) communication systems architecture for mobile, wireless local area networks (WLAN) and connectivity terminals. An important aspect of today's applications is the data rate increase, especially in connectivity standards like WiFI and WiMAX, because the user demands high Quality of Service (QoS). To increase the data rate we tend to use wideband or multi-standard architecture. The concept of software radio includes a self-reconfigurable radio link and is described here on its RF aspects. The term multi-radio is preferred. This chapter focuses on the transmitter, yet some considerations about the receiver are given. An important aspect of the architecture is that a transceiver is built with respect to the radio-communications signals. We classify them in section 2 by differentiating Continuous Wave (CW) and Impulse Radio (IR) systems. Section 3 is the technical background one has to consider for actual applications. Section 4 summarizes state-of-the-art high data rate architectures and the latest research in multi-radio systems. In section 5, IR architectures for Ultra Wide Band (UWB) systems complete this overview; we will also underline the coexistence and compatibility challenges between CW and IR systems

Direct Antenna Modulation using Frequency Selective Surfaces

In the coming years, the number of connected wireless devices will increase dramatically, expanding the Internet of Things (IoT). It is likely that much of this capacity will come from network densification. However, base stations are inefficient and expensive, particularly the downlink transmitters. The main cause of this is the power amplifier (PA), which must amplify complex signals, so are expensive and often only 30% efficient. As such, the cost of densifying cellular networks is high. This thesis aims to overcome this problem through codesign of a low complexity, energy efficient transmitter through electromagnetic design; and a waveform which leverages the advantages and mitigates the disadvantages of the new technology, while being suitable for supporting IoT devices. Direct Antenna Modulation (DAM) is a low complexity transmitter architecture, where modulation occurs at the antenna at transmit power. This means a non-linear PA can efficiently amplify the carrier wave without added distortion. Frequency Selective Surfaces (FSS) are presented here as potential phase modulators for DAM transmitters. The theory of operation is discussed, and a prototype DAM for QPSK modulation is simulated, designed and tested. Next, the design process for a continuous phase modulating antenna is explored. Simulations and measurement are used to fully characterise a prototype, and it is implemented in a line-of-sight end-to-end communications system, demonstrating BPSK, QPSK and 8-PSK. Due to the favourable effects of spread spectrum signalling on FSS DAM performance, Cyclic Prefix Direct Sequence Spread Spectrum (CPDSSS) is developed. Conventional spreading techniques are extended using a cyclic prefix, making multipath interference entirely defined by the periodic autocorrelation of the sequence used. This is demonstrated analytically, through simulation and with experiments. Finally, CPDSSS is implemented using FSS DAM, demonstrating the potential of this new low cost, low complexity transmitter with CPDSSS as a scalable solution to IoT connectivity

Realizing mobile multimedia systems over emerging fourth-generation wireless technologies

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (p. [161]-167) and index.by Pei-Jeng Kuo.M.Eng