Browsing by Author "Parssinen, Aarno"

Now showing 1 - 8 of 8
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    A 38.5-to-60.5 GHz LNA with Wideband Combiner Supporting Cartesian Beamforming Architecture
    (2021-09-13) Akbar, Rehman; Shaheen, Rana A.; Rahkonen, Timo; Tze, Cheung; Stadius, Kari; Parssinen, Aarno; Department of Electronics and Nanoengineering; Jussi Ryynänen Group; University of Oulu
    Current millimetre-wave (mmW) 5G NR standard supports multiple bands at 24.5/28/37/39/43/47GHz for communications. To cover several bands of the 5G NR and reaching lower end of unlicensed 60GHz band for 802.11ad, this work presents a wideband phased array front-end with LNA and two VGAs for scalar-only weighting function, and a wideband combining network of each signal weight in mmW domain for beamforming. In this work, two array elements are combined in two cascaded stages for extremely wideband operation. Combined load resonances are distributed and adjusted appropriately in each of the combining stages to achieve a flat response over the band of 38.5-60.5GHz. A single array path achieves rms gain of 8.5-12.5dB, noise figure of 6.2-8.1dB, and IP1dB of -33 to - 26dBm. The measurements show ≈ 6dB of array gain when the two phased array elements are combined in phase with +0.6dB to -0.4dB maximum gain error in the mmW VGAs. The prototype is implemented using 28nm CMOS.
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    6G Radio Requirements to Support Integrated Communication, Localization, and Sensing
    (2022) Wymeersch, Henk; Parssinen, Aarno; Abrudan, Traian E.; Wolfgang, Andreas; Haneda, Katsuyuki; Sarajlic, Muris; Leinonen, Marko E.; Keskin, Musa Furkan; Chen, Hui; Lindberg, Simon; Kyosti, Pekka; Svensson, Tommy; Yang, Xinxin; Department of Electronics and Nanoengineering; Katsuyuki Haneda Group; Chalmers University of Technology; University of Oulu; Qamcom Research and Technology AB; Ericsson AB; Lucent
    6G will be characterized by extreme use cases, not only for communication, but also for localization, and sensing. The use cases can be directly mapped to requirements in terms of standard key performance indicators (KPIs), such as data rate, latency, or localization accuracy. The goal of this paper is to go one step further and map these standard KPIs to requirements on signals, on hardware architectures, and on deployments. Based on this, system solutions can be identified that can support several use cases simultaneously. Since there are several ways to meet the KPIs, there is no unique solution and preferable configurations will be discussed.
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    Above-100 GHz wave propagation studies in the european project hexa-X for 6G channel modelling
    (2021-06-08) Kyosti, Pekka; Haneda, Katsuyuki; Conrat, Jean Marc; Parssinen, Aarno; Department of Electronics and Nanoengineering; Katsuyuki Haneda Group; University of Oulu; Orange S.A.
    We describe capabilities and plans to characterize above 100 GHz radio channel and propagation effects as part of a 6G research project Hexa-X. The starting point is the existing knowledge of radio propagation gathered by prior measurement and theoretical studies. Then we define measurement equipment, planned or performed campaigns, and discuss some challenges related to measurements at upper mm-wave frequencies. For several reasons the channel measurements are more time consuming on higher frequencies and it is not easy to collect enough data for statistical analysis. Hence we briefly introduce a stored channel model that will be developed based on the gathered channel measurement data. This initial channel model can be used as it is for physical layer studies through simulations and also as a basis for future channel models.
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    Analysis of Uplink and Downlink Spatial Channel Reciprocity When Using Asymmetric Transceiver
    (IEEE, 2024) Zhang, Peize; Kyosti, Pekka; Guzman, Mar Francis De; Haneda, Katsuyuki; Parssinen, Aarno; Department of Electronics and Nanoengineering; Katsuyuki Haneda Group; University of Oulu
    A novel millimeter-wave massive MIMO system using asymmetric transceiver, i.e., unequal number of transmitting (Tx) and receiving (Rx) radio frequency chains, is expected to maintain the advantages of conventional fully digital beamforming architectures, but partly reduce the implementation cost and power consumption. However, uplink and downlink radio channels may become non-reciprocal due to the different dimensions of Tx-Rx antenna arrays. In this paper, we analyze the reciprocity of radio channels observed by practical antenna patterns with different beamwidths. Two metrics are leveraged to measure spatial channel reciprocity based on 142 GHz outdoor channel measurement data and 28 GHz indoor ray-tracing simulation data. The power angular spectrum reciprocity of uplink and downlink radio channels does not hold when the beam pattern of base station Tx array becomes much narrower than that of Rx array. Meanwhile, it becomes increasingly likely that in the extreme case (e.g., significant beamwidth difference between Tx and Rx beam patterns), pronounced angle reciprocity can still be observed in the sparse channels with less multipath components.
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    Design of a 20-80 GHz down-conversion mixer for 5G wireless communication with 22nm CMOS
    (2020-03) Hurskainen, Henri; Akbar, Rehman; Stadius, Kari; Parssinen, Aarno; Department of Electronics and Nanoengineering; Jussi Ryynänen Group; University of Oulu
    This paper proposes a 20-80 GHz RF double-balanced mixer utilizing a hybrid down-conversion scheme. To achieve the down-conversion over the entire range, two mixers are operating in double-down-conversion for fixed IF of 3 GHz and RF is divided into low-band 20-44GHz and high-band 44-80GHz. For the low-band, the first mixer is bypassed and the second mixer used for down-conversion. For the high-band, both mixers are used for down-conversion. This results in reducing the LO tuning range by over 50% as compared to a regular sliding IF scheme. The design is evaluated using simulations of the designed mixer in 22nm CMOS technology, achieving a conversion gain of over 5 dB throughout the RF bandwidth, a minimum IIP3 of 4.9 dBm and minimum noise figure of 5.1 dB.
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    How many beams does sub-THz channel support
    (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2022-01) Kyosti, Pekka; De Guzman, Mar Francis; Haneda, Katsuyuki; Tervo, Nuutti; Parssinen, Aarno; Department of Electronics and Nanoengineering; Katsuyuki Haneda Group; University of Oulu
    Antenna, radio frequency (RF) circuit, algorithm, and system researchers on sub-THz RF are interested in knowing characteristics of corresponding radio channels. Among other things, a relevant question is the number of beams supported by the channel. From wideband directional propagation measurements one can estimate how many significant paths are present in a measurement location, but interpreting that to separable beams is not trivial. In this letter, we introduce three methods to approximate the number of beams that a measured power angular delay profile can support. We show also example evaluations and distribution functions of beam numbers, estimated from indoor D-band measurement data.
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    On the Feasibility of Out-of-Band Spatial Channel Information for Millimeter-Wave Beam Search
    (IEEE, 2023-05-01) Kyosti, Pekka; Zhang, Peize; Parssinen, Aarno; Haneda, Katsuyuki; Koivumaki, Pasi; Fan, Wei; Department of Electronics and Nanoengineering; Katsuyuki Haneda Group; University of Oulu; Aalborg University
    Prolonged beam alignment is the main source of overhead in mobile wireless communications at millimeter-wave (mm-wave) frequencies due to narrow beams following the requirement of high antenna gains. Out-of-band spatial information may be used in initial beam search when lower-frequency-band radios are operating in conjunction with mm-wave radios. The feasibility of using low-band channel information for coarse estimation of high-band beam directions strongly depends on the spatial congruence between the two frequency bands. In this work, we try to answer two related questions. First, how similar is the power angular spectrum (PAS) of propagation channels between two widely separated frequency bands? Then, what is the impact of practical antenna configurations on spatial channel similarity? We propose a beam directions-based metric to assess the power loss and the number of false directions if out-of-band spatial information is used instead of in- band information. This metric is more practical and useful than comparing the PASs directly. Point cloud ray-tracing and propagation measurement results across multiple frequency bands and environments are used to show that the degree of spatial similarity of beamformed channels is related to antenna beam widths, frequency gap, and radio link conditions.
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    A Wideband IF Receiver Chip for Flexibly Scalable mmWave Subarray Combining and Interference Rejection
    (IEEE, 2023-12-01) Akbar, Rehman; Klumperink, Eric A.M.; Tervo, Nuutti; Stadius, Kari; Rahkonen, Timo; Parssinen, Aarno; Department of Electronics and Nanoengineering; Jussi Ryynänen Group; University of Oulu; University of Twente
    Large-scale multibeam phased array systems suffer from interbeam interference (IBI) that should be canceled either in the analog or digital domain. In wideband systems such as fifth generation (5G), interference rejection over a wide bandwidth is challenging to achieve, not only due to nonidealities of the receiver chain but also due to the properties of the radio channel. This article presents a scalable IBI cancellation (IBIC) scheme at intermediate frequency (IF) using an IF receiver (IF-RX) chip. The IF-RX provides the flexibility of not just interference rejection between the subarrays but also wideband signal combining over multiple subarrays. It also provides wideband filtering before the analog-to-digital converter (ADC) to support 5G channel bandwidths of up to 800 MHz, high linearity, and low noise figure. A calibration method is proposed to find the cancellation coefficients for the IF-RX in measurements. Furthermore, a simplified over-the-air (OTA) IBIC model for analyzing rejection bandwidth limitations is presented. Interference rejection performance is demonstrated through the OTA measurements using 5G new radio (5G NR) signals. In the OTA measurements, 34-37-dB rejection was achieved for 50-100-MHz signals, while error vector magnitude (EVM) requirements of the 5G standards were met with good margins. Finally, the interference rejection over 4 × 100 MHz carrier aggregated 5G NR waveform was demonstrated.