Book•
Digital Compensation for Analog Front-Ends: A New Approach to Wireless Transceiver Design
09 Jun 2008-
TL;DR: In this article, the authors present a comprehensive overview of the analog front-end compensation for broadband wireless networks and provide a systematic approach to designing a digital communication system, including joint estimation of synchronization and non-ideality parameters.
Abstract: The desire to build lower cost analog front-ends has triggered interest in a new domain of research. Consequently the joint design of the analog front-end and of the digital baseband algorithms has become an important field of research. It enables the wireless systems and chip designers to more effectively trade the communication performance with the production cost. Digital Compensation for Analog Front-Ends provides a systematic approach to designing a digital communication system. It covers in detail the digital compensation of many non-idealities, for a wide class of emerging broadband standards and with a system approach in the design of the receiver algorithms. In particular, system strategies for joint estimation of synchronization and front-end non-ideality parameters are emphasized. The book is organized to allow the reader to gradually absorb the important information and vast quantity of material on this subject. The first chapter is a comprehensive introduction to the emerging wireless standards which is followed by a detailed description of the front-end non-idealities in chapter two. Chapter three then uses this information to explore what happens when the topics introduced in the first two chapters are merged. The book concludes with two chapters providing an in-depth coverage of the estimation and compensation algorithms. This book is a valuable reference for wireless system architects and chip designers as well as engineers or managers in system design and development. It will also be of interest to researchers in industry and academia, graduate students and wireless network operators. Presents a global, systematic approach to the joint design of the analog front-end compensation, channel estimation, synchronization and of the digital baseband algorithms Describes in depth the main front-end non-idealities such as phase noise, IQ imbalance, non-linearity, clipping, quantization, carrier frequency offset, sampling clock offset and their impact on the modulation Explains how the non-idealities introduced by the analog front-end elements can be compensated digitally Methodologies are applied to the emerging Wireless Local Area Network and outdoor Cellular communication systems, hence covering OFDM(A), SC-FDE and MIMO Written by authors with in-depth expertise developed in the wireless research group of IMEC and projects covering the main broadband wireless standards
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TL;DR: In this article, the state of this emerging photonic circuit design flow and its synergies with electronic design automation (EDA) is reviewed. And the similarities and differences between photonic and electronic design, and the challenges and opportunities that present themselves in the new photonic design landscape, such as variability analysis, photonic-electronic co-simulation and compact model definition.
Abstract: Silicon Photonics technology is rapidly maturing as a platform for larger-scale photonic circuits. As a result, the associated design methodologies are also evolving from componentoriented design to a more circuit-oriented design flow, that makes abstraction from the very detailed geometry and enables design on a larger scale. In this paper, we review the state of this emerging photonic circuit design flow and its synergies with electronic design automation (EDA). We cover the design flow from schematic capture, circuit simulation, layout and verification. We discuss the similarities and the differences between photonic and electronic design, and the challenges and opportunities that present themselves in the new photonic design landscape, such as variability analysis, photonic-electronic co-simulation and compact model definition. Silicon Photonics Circuit Design: Methods, Tools and
355 citations
Cites methods from "Digital Compensation for Analog Fro..."
...Similar approaches have been used in analog electronics, where digital feedback circuits are used to compensate the deficiencies of imperfect analog electronic elements [211]....
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TL;DR: The fundamental technical contributions to efficient digital signal processing for Massive MIMO are summarized, and the opportunities and constraints on operating on low-complexity RF and analog hardware chains are clarified.
Abstract: Massive MIMO is a compelling wireless access concept that relies on the use of an excess number of base-station antennas, relative to the number of active terminals. This technology is a main component of 5G New Radio and addresses all important requirements of future wireless standards: a great capacity increase, the support of many simultaneous users, and improvement in energy efficiency. Massive MIMO requires the simultaneous processing of signals from many antenna chains, and computational operations on large matrices. The complexity of the digital processing has been viewed as a fundamental obstacle to the feasibility of Massive MIMO in the past. Recent advances on system-algorithm-hardware co-design have led to extremely energy-efficient implementations. These exploit opportunities in deeply-scaled silicon technologies and perform partly distributed processing to cope with the bottlenecks encountered in the interconnection of many signals. For example, prototype ASIC implementations have demonstrated zero-forcing precoding in real time at a 55 mW power consumption (20 MHz bandwidth, 128 antennas, and multiplexing of 8 terminals). Coarse and even error-prone digital processing in the antenna paths permits a reduction of consumption with a factor of 2 to 5. This article summarizes the fundamental technical contributions to efficient digital signal processing for Massive MIMO. The opportunities and constraints on operating on low-complexity RF and analog hardware chains are clarified. It illustrates how terminals can benefit from improved energy efficiency. The status of technology and real-life prototypes discussed. Open challenges and directions for future research are suggested.
65 citations
Cites methods from "Digital Compensation for Analog Fro..."
...We consider a polynomial memoryless model [18] for the non-linear behaviour of the PA....
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TL;DR: Analytical and numerical results demonstrate that the direct mode can outperform the amplify-and-forward mode even under moderate levels of uncompensated I/Q imbalance.
Abstract: We analyze the outage performance of half-duplex amplify-and-forward relaying in an OFDM system with MRC detection in the presence of I/Q imbalance and compare it with that of the direct transmission mode. Both analytical and numerical results demonstrate that the direct mode can outperform the amplify-and-forward mode even under moderate levels of uncompensated I/Q imbalance. The cross-over I/Q imbalance levels are determined analytically to be inversely proportional to the cube of the signal constellation size. In addition, we present a low-complexity receiver-based digital baseband I/Q imbalance compensation scheme for the amplify-and-forward mode and analyze its EVM performance. Furthermore, we derive accurate analytical approximations for the EVM performance as a function of relay location and I/Q imbalance level with and without compensation.
59 citations
Cites background or methods from "Digital Compensation for Analog Fro..."
...The time-domain (TD) baseband representation of the IQI-impaired signal is given by g IQI(t) [6] where...
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...We consider frequency-independent2 IQI caused by the gain and phase mismatches between the I and Q branches paths [6] and they are denoted, respectively, by t/r x and θ t/r x where the subscript x is the terminal identifier (BST, RS or UE) and the superscript t/r denotes the up/down-conversion process, respectively....
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...120576 offset (CFO), phase noise (PN) and I/Q imbalance (IQI) [6]....
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TL;DR: In this paper, measurement results of a low-cost hardware-based calibration are presented and the drawbacks are discussed leading to the utilization of a recently introduced relative calibration.
Abstract: The combination of OFDM with joint pre-processing in adaptive multi-antenna systems offers both an ease of equalization in frequency-selective channels and keeping the signal processing at the mobile stations simple. In addition, the spatial dimension can be efficiently exploited to ensure high system throughput. With the utilization of higher-order modulation the performance of the system is highly sensitive to multiple access interference and nonorthogonal subchannels due to hardware impairments or insufficient adaptation to the current channel conditions. A further source of error in TDD systems are the non-reciprocal transceivers inhibiting the baseband-to-baseband channel reciprocity required for accurate channel state acquisition based on the uplink channel estimate. In this paper, measurement results of a low-cost hardware-based calibration are presented and the drawbacks are discussed leading to the utilization of a recently introduced relative calibration. The latter is applied to an OFDM system and achieves or at least approximates the baseband-to-baseband reciprocity. Thus, it enables the link adaptation using the uplink channel state information. Furthermore, preliminary hardware implementations of the relative calibration running on a real-time system show accurate results.
59 citations
TL;DR: GFDM reveals to be the most promising contender, with the best spectral efficiency and the smallest complexity overhead compared to OFDM, and UFMC and RB-F-OFDM are finally the closest to OfDM and benefit therefore from a better compatibility with existing systems, even if their performance is generally lower.
Abstract: This paper presents an extensive and fair comparison among the most promising waveform contenders for the 5G air interface. The considered waveform contenders, namely filter-bank multi-carrier (FBMC), universal-filtered multi-carrier (UFMC), generalized frequency-division multiplexing (GFDM) and resource-block filtered orthogonal frequency-division multiplexing (RB-F-OFDM) are compared to OFDM used in 4G in terms of spectral efficiency, numerical complexity, robustness towards multi-user interference (MUI) and resilience to power amplifier non-linearity. FBMC shows the best spectral containment and reveals to be almost insensitive to multi-user interference. It however suffers from its bad spectral efficiency for short bursts and from its poor multiple input multiple output (MIMO) compatibility. GFDM reveals to be the most promising contender, with the best spectral efficiency and the smallest complexity overhead compared to OFDM. It is also the most resilient to multi-user interference after FBMC and is MIMO compatible as soon as the interference can be managed. UFMC and RB-F-OFDM are finally the closest to OFDM and benefit therefore from a better compatibility with existing systems, even if their performance is generally lower than FBMC and GFDM.
57 citations
Cites background from "Digital Compensation for Analog Fro..."
...12 by reporting the guard band to insert between users to reach an MSE of −30 dB for the user of interest....
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...7MSE of the UoI in asynchronized uplink FDMA scenario as a function of the relative power of the interferers....
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...The in-band distortion sensitivity of each waveform is quantified in Table 7 depicting the maximum OBO (OBOID max) such that the receiver MSE reaches −25 dB....
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...This windowing introduces a convolution effect in the frequency domain explaining the saturation of the MSE when the power of the interferers becomes negligible compared to the UoI....
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...The receiver MSE of each waveform as a function of the OBO is illustrated in Fig....
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