TL;DR: An approach is presented for minimizing power consumption for digital systems implemented in CMOS which involves optimization at all levels of the design and has been applied to the design of a chipset for a portable multimedia terminal that supports pen input, speech I/O and full-motion video.
Abstract: An approach is presented for minimizing power consumption for digital systems implemented in CMOS which involves optimization at all levels of the design. This optimization includes the technology used to implement the digital circuits, the circuit style and topology, the architecture for implementing the circuits and at the highest level the algorithms that are being implemented. The most important technology consideration is the threshold voltage and its control which allows the reduction of supply voltage without significant impact on logic speed. Even further supply reductions can be made by the use of an architecture-based voltage scaling strategy, which uses parallelism and pipelining, to tradeoff silicon area and power reduction. Since energy is only consumed when capacitance is being switched power can be reduced by minimizing this capacitance through operation reduction choice of number representation, exploitation of signal correlations, resynchronization to minimize glitching, logic design, circuit design, and physical design. The low-power techniques that are presented have been applied to the design of a chipset for a portable multimedia terminal that supports pen input, speech I/O and full-motion video. The entire chipset that performs protocol conversion, synchronization, error correction, packetization, buffering, video decompression and D/A conversion operates from a 1.1 V supply and consumes less than 5 mW. >
TL;DR: An integrated SiGe superheterodyne RX/TX pair capable of Gb/s data rates in the 60GHz band is described and achieves 10% PAE in the final stage.
Abstract: An integrated SiGe superheterodyne RX/TX pair capable of Gb/s data rates in the 60GHz band is described. The 6dB NF RX includes an image-reject LNA, a multistage down-converter with on-chip IF filters, a frequency tripler, a PLL, and baseband outputs. The 10 to 12dBm P1dBTX achieves 10% PAE in the final stage. It includes a PA, image-reject driver, multistage up-converter with on-chip filters, tripler, and PLL
TL;DR: The nexmon CSI Extractor Tool allows per-frame CSI extraction for up to four spatial streams using up toFour receive chains on modern Broadcom and Cypress Wi-Fi chips with up to 80MHz bandwidth in both the 2.4 and 5GHz bands.
Abstract: Modern wireless transmission systems heavily benefit from knowing the channel response. The evaluation of Channel State Information (CSI) during the reception of a frame preamble is fundamental to properly equalizing the rest of the transmission at the receiver side. Reporting this state information back to the transmitter facilitates mechanisms such as beamforming and MIMO, thus boosting the network performance. While these features are an integral part of standards such as 802.11ac, accessing CSI data on commercial devices is either not possible, limited to outdated chipsets or very inflexible. This hinders the research and development of innovative CSI-dependent techniques including localization, object tracking, and interference evaluation. To help researchers and practitioners, we introduce the nexmon CSI Extractor Tool. It allows per-frame CSI extraction for up to four spatial streams using up to four receive chains on modern Broadcom and Cypress Wi-Fi chips with up to 80MHz bandwidth in both the 2.4 and 5GHz bands. The tool supports devices ranging from the low-cost Raspberry Pi platform, over mobile platforms such as Nexus smartphones to state-of-the-art Wi-Fi APs. We release all tools and Wi-Fi firmware patches as extensible open source project. It includes our user-friendly smartphone application to demonstrate the CSI extraction capabilities in form of a waterfall diagram.
TL;DR: Using measurement of actual systems running scientific, commercial and productivity workloads, power models for six subsystems on two platforms are developed and validated and it is possible to estimate system power consumption without the need for power sensing hardware.
Abstract: This paper proposes the use of microprocessor performance counters for online measurement of complete system power consumption. The approach takes advantage of the "trickle-down” effect of performance events in microprocessors. While it has been known that CPU power consumption is correlated to processor performance, the use of well-known performance-related events within a microprocessor such as cache misses and DMA transactions to estimate power consumption in memory and disk and other subsystems outside of the microprocessor is new. Using measurement of actual systems running scientific, commercial and productivity workloads, power models for six subsystems (CPU, memory, chipset, I/O, disk, and GPU) on two platforms (server and desktop) are developed and validated. These models are shown to have an average error of less than nine percent per subsystem across the considered workloads. Through the use of these models and existing on-chip performance event counters, it is possible to estimate system power consumption without the need for power sensing hardware.
TL;DR: This paper presents a 802.11ad radio chipset capable of SC and OFDM modulation using a 16TX-16RX beamforming RF front-end, complete with an antenna array that supports polarization diversity.
Abstract: The IEEE 802.11ad standard supports PHY rates up to 6.7Gb/s on four 2GHz-wide channels from 57 to 64GHz. A 60GHz system offers higher throughput than existing 802.11ac solutions but has several challenges for high-volume production including: integration in the host platform, automated test, and high link loss due to blockage and polarization mismatch. This paper presents a full-featured 802.11ad chipset capable of SC and OFDM modulation using a 16TX-16RX beamforming RF front-end, complete with an antenna array that supports polarization diversity. To aid low-cost integration in PC platforms, a single coaxial cable interface is used between chips. The chipset includes MAC, PHY, and RF with a PCIeTM interface and is capable of maintaining a link of 4.6Gb/s (PHY rate) at 10m.