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173 results on '"Kosunen, Marko"'

2. Adaptive Nonlinear RF Cancellation for Improved Isolation in Simultaneous Transmit-Receive Systems

Author

Kiayani, Adnan, Waheed, Muhammad Zeeshan, Anttila, Lauri, Abdelaziz, Mahmoud, Korpi, Dani, Syrjälä, Ville, Kosunen, Marko, Stadius, Kari, Ryynänen, Jussi, and Valkama, Mikko

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

This paper proposes an active radio frequency (RF) cancellation solution to suppress the transmitter (TX) passband leakage signal in radio transceivers supporting simultaneous transmission and reception. The proposed technique is based on creating an opposite-phase baseband equivalent replica of the TX leakage signal in the transceiver digital front-end through adaptive nonlinear filtering of the known transmit data, to facilitate highly accurate cancellation under a nonlinear TX power amplifier (PA). The active RF cancellation is then accomplished by employing an auxiliary transmitter chain, to generate the actual RF cancellation signal, and combining it with the received signal at the receiver (RX) low noise amplifier (LNA) input. A closed-loop parameter learning approach, based on the decorrelation principle, is also developed to efficiently estimate the coefficients of the nonlinear cancellation filter in the presence of a nonlinear TX PA with memory, finite passive isolation, and a nonlinear RX LNA. The performance of the proposed cancellation technique is evaluated through comprehensive RF measurements adopting commercial LTE-Advanced transceiver hardware components. The results show that the proposed technique can provide an additional suppression of up to 54 dB for the TX passband leakage signal at the RX LNA input, even at considerably high transmit power levels and with wide transmission bandwidths. Such novel cancellation solution can therefore substantially improve the TX-RX isolation, hence reducing the requirements on passive isolation and RF component linearity, as well as increasing the efficiency and flexibility of the RF spectrum use in the emerging 5G radio networks., Comment: accepted to IEEE

Published
2017
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8. Digital Polar Transmitters for Massive MIMO: Sum-Rate and Power Efficiency Analysis

Author

Xu, Guixian, Lampu, Vesa, Kosunen, Marko, Unnikrishnan, Vishnu, Ryynanen, Jussi, Valkama, Mikko, and Anttila, Lauri

Abstract

In this article, we comprehensively investigate the potential of the digital polar radio transmitter architecture for multi-user massive multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) downlink system. In terms of throughput performance, we derive a lower bound for the average sum-rate achievable with Gaussian signaling inputs and zero-forcing (ZF) precoding based on Bussgang decomposition. By diagonal approximation, we derive an approximate, yet accurate, model for the distortion caused by uniform polar quantization, which can be used to evaluate the corresponding sum-rate in closed form. To assess the power efficiency, we provide power consumption models with realistic parameters and values for the quantized polar and Cartesian transmitters, based on state-of-the-art integrated circuit (IC) designs and measurements. Extensive numerical results demonstrate that the proposed quantized polar transmitter can enable excellent performance in terms of average sum-rate, symbol error rate (SER), and out-of-band (OOB) emission level, compared to the Cartesian architecture. Furthermore, the power consumption comparisons show that the digital polar transmitter can save more than 36% in the energy consumption under 64-antenna setting in typical 5G enhanced mobile broadband use cases, thus making it highly appealing for future power-efficient massive MIMO transmitter implementations.

Published
2024
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9. Reconfigurable Signal Processing and DSP Hardware Generator for 5G and Beyond Transmitters

Author

Ghosh, Agnimesh, Spelman, Andrei, Cheung, Tze Hin, Boopathy, Dhanashree, Stadius, Kari, Gomony, Manil Dev, Valkama, Mikko, Ryynanen, Jussi, Kosunen, Marko, and Unnikrishnan, Vishnu

Abstract

The digital front-end of the communication transceivers envisioned for fifth-generation (5G) and beyond requires highly configurable high-performance digital signal processing (DSP) hardware operating at very high sampling rates to accommodate increasing signal bandwidths and support a range of modulation schemes and transmitter architectures. In this article, we present an efficient implementation of a highly configurable DSP hardware generator that can generate high-performance DSP hardware for multiple transmitter architectures including Cartesian, polar, outphasing, and multilevel outphasing modulators. The generated hardware unit, which consists of multistage multirate filters and other required DSP operations, runs at sample rates up to 4 GHz. The hardware supports an adjacent channel leakage ratio (ACLR) down to −48 dB and an error vector magnitude (EVM) of 0.78% with a 7-bit phase signal at a sampling rate of 4 GHz for multilevel outphasing modulation. Digital synthesis of the circuit in a 5-nm complimentary metal-oxide semiconductor (CMOS) process yields a core area consumption of 0.01 mm2 and an estimated power consumption of 37.2 mW for a 200-MHz bandwidth 5G new radio (NR) baseband (BB) signal.

Published
2024
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20. Leveraging frequency agility of an MIMO antenna cluster with a transmitter IC.

Author

Saleem, Ali Raza, Luomaniemi, Rasmus, Lehtovuori, Anu, Stadius, Kari, Kosunen, Marko, Viikari, Ville, and Ryynänen, Jussi

Subjects
FREQUENCY agility, ANTENNAS (Electronics), TRANSMITTERS (Communication), MOBILE antennas, INTEGRATED circuits
Abstract

This paper presents the prototype demonstration where an integrated transmitter circuit drives a mobile handset terminal antenna in order to provide frequency tunability and multiple input multiple output (MIMO) operation across the 0.5–4.5 GHz frequency range. The transmitter implementation incorporates on-chip weighted signal generation, i.e. amplitude and phase scaling to provide sufficient MIMO performance in the low band (700–960 MHz) and in the high band (1.5–4.5 GHz). In the transmitter, two antenna elements are used for MIMO operation in the low band and another two in the high band. The transmitter integrated circuit (IC) is fabricated in a 28 nm bulk CMOS technology with an active on-chip area of 0.2 mm $^2$. A custom antenna measurement procedure is proposed here in order to support and verify active antenna measurements with transmitter IC. A measurement procedure for the transmitter system comprising the transmitter IC and four antenna clusters is developed and discussed in comparison with traditional passive antenna measurements. The measurement results demonstrate that the transmitter IC driving the antenna clusters provides total antenna efficiency of $-6.5$ dB to $-1.5$ dB, and envelope correlation coefficient below 0.4 across the designated frequency bands. The results indicate that the implemented transmitter IC successfully tunes frequency response of the antenna clusters, and enhances the MIMO operation of such mobile antennas. [ABSTRACT FROM AUTHOR]

Published
2023
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28. A 1.5-5-GHz Integrated RF Transmitter Front End for Active Matching of an Antenna Cluster

Author

Saleem, Ali, Stadius, Kari, Hannula, Jari-Matti, Lehtovuori, Anu, Kosunen, Marko, Viikari, Ville, Ryynänen, Jussi, Jussi Ryynänen Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University

Subjects
wideband antenna tuning, Hardware_GENERAL, Multiport antenna, Hardware_INTEGRATEDCIRCUITS, reconfigurable antenna, transmitter
Abstract

openaire: EC/H2020/704947/EU//ADVANTAG5 Lataa oa, kun julkaistu. A recently proposed method for realizing frequency-reconfigurable antennas across a wideband is based on adjusting the feed amplitudes and phases of a multiport antenna. In this article, we demonstrate the feasibility of the method, for the first time, with a conjunction of an integrated RF transmitter and a four-element antenna cluster. The implementation performs on-chip amplitude and phase tuning with supply scaling and delay tuning circuits to tune the antenna cluster without requirement of matching network. The antenna cluster is built with four closely spaced antenna elements implemented on a printed circuit board. The transmitter integrated circuit (IC) is implemented in a 28-nm CMOS process with the chip size of 0.85 mm x 0.95 mm, including pads. The proof-of-concept implementation demonstrates tunability across a wideband from 1.5 to 5 GHz.

Published
2020

37. A 2–5.5 GHz Beamsteering Receiver IC With 4-Element Vivaldi Antenna Array

Author

Zahra, Mahwish, primary, Kempi, Ilia, additional, Haarla, Jaakko, additional, Antonov, Yury, additional, Khonsari, Zahra, additional, Miilunpalo, Toni, additional, Ahmed, Nouman, additional, Inkinen, Juha, additional, Unnikrishnan, Vishnu, additional, Lehtovuori, Anu, additional, Viikari, Ville, additional, Anttila, Lauri, additional, Valkama, Mikko, additional, Kosunen, Marko, additional, Stadius, Kari, additional, and Ryynanen, Jussi, additional

Published
2020
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39. A GSM/EDGE/WCDMA modulator with on-chip D/A converter for base stations

Author

Vankka, Jouko, Ketola, Jaakko, Sommarek, Johan, Vaananen, Olli, Kosunen, Marko, and Halonen, Kari A.I.

Subjects
Control systems, Electric current converters, Modulators (Electronics), Electric current converter, Business, Computers and office automation industries, Electronics, Electronics and electrical industries
Abstract

A global system for mobile communication (GSM)/enhanced data rates for GSM evolution (EDGE)/wide-band code division multiple access (WCDMA) modulator with a 14-bit on-chip digital-to-analog (D/A) converter is presented. The modulator consists of several digital signal processing building blocks, including a programmable pulse shaping filter, interpolation filters, resampler, cordinate rotation digital computer (CORDIC) rotator, programmable output power level controller and ramping unit, and x/sinx filter. The precompensation filter, which compensates the sinc droop above the Nyquist frequency, makes it possible to use WCDMA signal images for up-conversion. The new programmable up/down unit allows power ramping on a time-slot basis as specified for GSM, EDGE and time division duplex (TDD)-WCDMA. The multistandard modulator meets the spectral, phase and error vector magnitude (EVM) specifications. The die area of the chip is 22.09 [mm.sup.2] in 0.38-[micro]m CMOS technology. Power consumption is 1.7 W at 3.3 V with 110 MHz. Index Terms--Cordinate rotation digital computer (CORDIC), current steering digital-to-analog (D/A) converter, multicarrier, multistandard modulator, power control, power ramping, resampler.

Published
2002

46. A 1.5-1.9-GHz all-digital tri-phasing transmitter with an integrated multilevel class-D power amplifier achieving 100-MHz RF bandwidth

Author

Lemberg, Jerry, Martelius, Mikko, Roverato, Enrico, Antonov, Yury, Nieminen, Tero, Stadius, Kari, Anttila, Lauri, Valkama, Mikko, Kosunen, Marko, Ryynanen, Jussi, Department of Electronics and Nanoengineering, Tampere University, Aalto-yliopisto, Aalto University, Electrical Engineering, and Research group: Wireless Communications and Positioning

Subjects
213 Electronic, automation and communications engineering, electronics, class-D power amplifier (PA), All-digital transmitter, multilevel outphasing, tri-phasing, digital interpolating phase modulator (DIPM)
Abstract

openaire: EC/H2020/704947/EU//ADVANTAG5 We present a prototype RF transmitter with an integrated multilevel class-D power amplifier (PA), implemented in 28-nm CMOS. The transmitter utilizes tri-phasing modulation, which combines three constant-envelope phase-modulated signals with coarse amplitude modulation in the PA. This new architecture achieves the back-off efficiency of multilevel outphasing, without linearity-degrading discontinuities in the RF output waveform. Because all signal processing is performed in the time domain up to the PA, the entire system is implemented with digital circuits and structures, thus also enabling the use of synthesis and place-and-route CAD tools for the RF front end. The effectiveness of the digital tri-phasing concept is supported by extensive measurement results. Improved wideband performance is validated through the transmission of orthogonal frequency-division multiplexing (OFDM) bandwidths up to 100 MHz. Enhanced reconfigurability is demonstrated with non-contiguous carrier aggregation and digital carrier generation between 1.5 and 1.9 GHz without a frequency synthesizer. For a 20-MHz 256-QAM OFDM signal at 3.5% error vector magnitude (EVM), the transmitter achieves 22.6-dBm output power and 14.6% PA efficiency. Thanks to the high linearity enabled by tri-phasing, no digital predistortion is needed for the PA.

Published
2019

47. Spatial Interpolation of Cyclostationary Test Statistics in Cognitive Radio Networks

Author

Chaudhari, Sachin, Kosunen, Marko, Mäkinen, Semu, Chandrasekaran, Ramanathan, Oksanen, Jan, Laatta, Markus, Ryynanen, Jussi, Koivunen, Visa, Valkama, Mikko, International Institute of Information Technology Hyderabad, Department of Micro and Nanosciences, Indian Institute of Technology Madras, Dept Signal Process and Acoust, Tampere University of Technology, Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University

Subjects
Databases, Kriging, radio environment map, cyclostationary detection, Hardware, spectrum sensing, Cognitive radio, spatial estimation, Detectors, Interference, Mobile communication, energy detection, Interpolation
Abstract

The focus of this paper is on evaluating different spatial interpolation methods for the construction of radio environment map (REM) using field measurements obtained by cyclostationary based mobile sensors. Mobile sensing devices employing cyclostationary detectors provide lot of advantages compared to widely used energy detectors such as robustness to noise uncertainty and ability to distinguish among different primary user signals. However, mobile sensing results are not available at locations between the sensors making it difficult for a secondary user (possibly without a spectrum sensor) to decide whether or not to use primary user resources at that location. To overcome this, spatial interpolation of test statistics measured at limited number of locations can be carried out to create a channel occupancy map at unmeasured locations between the sensors. For this purpose, different spatial interpolation techniques for the cyclostationary test statistic have been employed in this paper such as inverse distance weighting (IDW), ordinary Kriging (OK), and universal Kriging (UK). The effectiveness of these methods is demonstrated by applying them on extensive real-world field measurement data obtained by mobile-phone-compliant spectrum sensors. The field measurements were carried out using four mobile spectrum sensors measuring eight DVB-T channels at more than hundred locations encompassing roughly one-third of the area of the city of Espoo in Finland. The accuracy of the spatial interpolation results based on the field measurements is determined using the cross validation approach with the widely used root mean square error (RMSE) as the metric. Field measurement results indicate that reliable results with spatial coverage can be achieved using Kriging for cyclostationary based test statistics. Comparison of spatial interpolation results of cyclostationary test statistics is also carried out with those of energy values obtained during the measurement campaign in the form of received signal strength indicator (RSSI). Comparison results clearly show the performance improvement and robustness obtained by the use of cyclostationary based detectors instead of energy detectors.

Published
2018

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