A fully integrated technique for wideband cancellation of transmitter (TX) self-interference (SI) in the RF domain is proposed multiband frequency-division duplexing (FDD) and full-duplex (FD) wireless applications. Integrated SI (SIC) accomplished through: 1) a bank tunable, reconfigurable second-order high-Q bandpass filters canceller that emulate antenna interface's isolation (essentially frequency-domain equalization domain) 2) linear N-path G <sub...

Full duplex wireless has drawn significant interest in the recent past due to potential for doubling network capacity physical layer and offering numerous other benefits at higher layers. However, implementation of integrated full radios is fraught with several fundamental challenges. Achieving levels self-interference cancellation required over wide bandwidths mandated by emerging standards challenging an circuit implementation. The dynamic range limitations electronics restrict transmitter...

Recently, we demonstrated the first CMOS nonmagnetic nonreciprocal passive circulator based on N-path filters that uses time variance to break reciprocity. Here, analysis of performance metrics, such as loss, isolation, linearity, and tuning range, is presented in terms design parameters. The verified by measured a 65-nm prototype exhibits 1.7 dB loss transmitter-antenna (TX-ANT) antenna-receiver (ANT-RX) paths, has high isolation [TX-RX, up 50 through 20-dB bandwidth (BW) 32 MHz] range...

Full-duplex (FD) is an emergent wireless communication paradigm where the transmitter (TX) and receiver (RX) operate at same time frequency. The fundamental challenge with FD tremendous amount of TX self-interference (SI) RX. Low-power applications relax system requirements [1], but -6dBm transmit power, 10MHz signal bandwidth 12dB NF budget still requires 86dB SI suppression to reach -92dBm noise floor. Recent research has focused on techniques for integrated cancellation (SIC) in receivers...

A technique for active cancellation of transmitter self-interference in wideband receivers is presented. The TX leakage circuitry embedded within a noise-cancelling low-noise transconductance amplifier (LNTA) so that the noise and distortion are cancelled, resulting noise-cancelling, cancelling receiver (NC-SIC RX). second-point RX band performed after LNTA impact second canceller reduced. Theoretical analyses related to benefits limits as well simultaneous 0.3-1.7 GHz with proposed...

A fundamental challenge of full-duplex (FD) wireless is the implementation low-cost, small-form-factor, integrated shared-antenna (ANT) interfaces with low loss, noise, high TX-RX isolation, and large TX power handling. Providing more isolation in ANT interface that robust to environmental variations lowers self-interference cancellation (SIC) dynamic range required RF, analog baseband (BB), digital domains. Reciprocal shared-ANT interfaces, such as electrical-balance duplexers,...

Previously, we presented a non-magnetic, nonreciprocal N-path-filter-based circulator-receiver (circ.-RX) architecture for full-duplex (FD) wireless which merges commutation-based linear periodically-time-varying (LPTV) non-magnetic circulator with down-converting mixer and directly provides the baseband (BB) receiver signals at its output, while suppressing noise contribution of one set commutating switches. The also incorporates an on-chip balance network to enhance transmitter...

Full-duplex communication has the potential to substantially increase throughput in wireless networks. However, benefits of full-duplex are still not well understood. In this paper, we characterize rate gains both single-channel and multi-channel use cases. For case, quantify gain as a function remaining self-interference SNR values. We also provide sufficient condition under which sum uplink downlink rates on channel is concave transmission power levels. Building these results, consider...

In this paper, a 0.8-to-1.4GHz receiver with tunable, reconfigurable RF SI canceller at the RX input is presented that supports >20MHz cancellation BW across variety of antenna interfaces (nearly 10× improvement over conventional canceller). This accomplished by (i) bank 2nd-order high-Q bandpass filters in to emulate interface isolation (essentially frequency-domain equalization), and (ii) linear N-path Gm-C filter implementation embedded variable attenuation phase shifting. For FDD, SIC...

N-path switched- RC circuits are a promising solution for realizing tunable high- Q filters on chip. Here, novel method of embedding phase-shifting functionality into the two-port N- path filter response by shifting phase input and output clock sets relative to each other is introduced. Furthermore, design allows us embed variable attenuation that can be useful in applications such as wideband self-interference cancellers phased-array front ends, where filtering, shifting, gain functionally...

Full-duplex (FD) wireless can significantly enhance spectrum efficiency but requires tremendous amount of self-interference (SI) cancellation. Recent advances in the RFIC community enabled wideband RF SI cancellation (SIC) integrated circuits (ICs) via frequency-domain equalization (FDE), where filters channelize signal path. Unlike other FD implementations, that mostly rely on delay lines, FDE-based cancellers be realized small-form-factor devices. However, fundamental limits and higher...

This paper presents a wide-band fractional-N frequency synthesizer for multi-standard cellular and short-range wireless communication receivers. The covers the band from 1.8 to 6 GHz supports standards of DCS1800, WCDMA, TD-SCDMA, WLAN802.11 a/b/g Bluetooth. Architecture design planning are carefully performed tradeoff wide range power efficiency. A quadrature voltage-controlled oscillator (QVCO) with new phase shifter scheme is developed which shows better noise performance more stable...

Since the invention of radio, transmission and reception have been separated to protect receiver (Rx) from being jammed by self-interference (SI), i.e., interference that comes colocated radio transmitter (Tx). This separation is called duplexing. Today's wireless systems still rely on duplexing avoid SI-many short-range or local area radios, such as Bluetooth WiFi transceivers, transmit receive in nonoverlapping time slots, time-division (TDD), while other modern systems, majority today's...

Ubiquitous multicore processors nowadays rely on an integrated packet-switched network for cores to exchange and share data. The performance of these intra-chip networks is a key determinant the processor speed and, at high core counts, becomes important bottleneck due scalability issues. To address this, several works propose use mm-wave wireless interconnects communication demonstrate that, thanks their low-latency broadcast system-level flexibility, this new paradigm could break barriers...

Cost savings have become a significant challenge in the management of data centers. In this paper, we show that, besides energy consumption, service level agreement(SLA) violations also severely degrade cost-efficiency We present online VM placement algorithms for increasing cloud provider's revenue. First, First-Fit and Harmonic algorithm are devised without considering migrations. Both get same performance worst-case analysis, equal to lower bound competitive ratio. However, could create...

This paper demonstrates a passive low-insertionloss (IL) RF filter with periodic passbands and capable of sparsifying the spectrum from 238 to 526 MHz for sparse Fourier transform (SFT)-based sensing. The demonstrated employs LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> lateral overtone bulk acoustic resonators (LOBARs) high-quality factors (Qs), large electromechanical coupling (k...

This paper presents a dual-mode voltage-controlled oscillator (DMVCO) and DMVCO-based wideband frequency synthesizer for software-defined radio applications. The DMVCO allows the to leverage single-sideband (SSB) mixing, power efficient approach, high-frequency local (LO) signal generation, without need of poly-phase filter or quadrature (QVCO). When compared QVCO solution provide continuous LO signals gaps. is implemented in 0.13-μm CMOS technology, occupying an active area 2.2 mm <sup...

The demand for lower cost and form factor increased re-configurability in wireless systems has driven the investigation of blocker-tolerant software-defined radios [1-4]. While promising, a reduction system form-factor will result isolation among antennas due to co-existence multiple ratios or within duplexers FDD their reduced size and/or re-configurability. Out-of-band (OOB) powerful modulated TX-leakage limited antenna/duplexer imposes challenges that are more severe than those posed by...

A major drawback of digital transmitters (DTX) is the absence a reconstruction filter after digital-to-analog conversion which causes baseband quantization noise to get upconverted radio frequency and amplified at output transmitter. In high power transmitters, this can be so strong as prevent their use in frequency-division duplexing systems due receiver desensitization or impose stringent coexistence challenges. paper, we describe DTX that embeds mixed-domain multi-tap finite-impulse...

A wideband analog/RF interference cancellation technique that is able to autonomously adapt itself timevarying channels and scale its dc power based on the number of multiple-input-multiple-output (MIMO) array elements presented. Least-mean square (LMS) adaptive circuitry co-designed with partially embedded in a RF/analog canceller gain-boosted mixer-first receiver (RX), significantly reducing system complexity while achieving rapid (microsecond-scale) adaptation. In addition, proposed...

Full-duplex wireless is an exciting emerging communication paradigm that also poses tremendous challenges at virtually every layer: from the antenna interface and integrated circuits (ICs) systems to network layer. This paper covers recent advances Columbia University across all these dimensions. Several potential full-duplex system architectures are appropriate for different application spaces discussed. Specific research include (i) a novel CMOS non-reciprocal circulator utilizes...

A demonstration of a real-time full-duplex wireless link is presented, in which pair transceivers perform simultaneous transmission and reception on the same frequency channel. transceiver composed custom-designed small-form-factor analog self-interference canceller, digital cancellation implementation integrated with National Instruments Universal Software Radio Peripheral (USRP). An adaptive canceller tuning mechanism adjusts to environmental changes. We demonstrate practicality robustness...

This article presents an agile passive-mixer-first superheterodyne RF front-end that utilizes a gigahertz acoustic filter as its intermediate-frequency (IF) load-essentially mixer-first acoustic-filtering front-end. The passive mixer frequency-translates sharp but fixed-frequency response to much higher and mixer-clock-defined tunable frequency while preserves input matching, high linearity, introduces minimal loss. In contrast low- or zero-IF receivers which often use active filters at...

This demonstration presents a practical real-time full-duplex wireless link consisting of two transceivers. Our prototyped transceiver contains custom-designed RF self-interference canceller and National Instruments (NI) Universal Software Radio Peripheral (USRP). The discrete-component-based emulates compact RFIC implementation, which uses programmable bandpass filters to achieve wideband cancellation through the technique frequency domain equalization. We demonstrate suppression across...