Towards versatile access networks (Chapter 3)

Compared to its previous generations, the 5th generation (5G) cellular network features an additional type of densification, i.e., a large number of active antennas per access point (AP) can be deployed. This technique is known as massive multipleinput multiple-output (mMIMO) [1]. Meanwhile, multiple-input multiple-output (MIMO) evolution, e.g., in channel state information (CSI) enhancement, and also on the study of a larger number of orthogonal demodulation reference signal (DMRS) ports for MU-MIMO, was one of the Release 18 of 3rd generation partnership project (3GPP Rel-18) work item. This release (3GPP Rel-18) package approval, in the fourth quarter of 2021, marked the start of the 5G Advanced evolution in 3GPP. The other items in 3GPP Rel-18 are to study and add functionality in the areas of network energy savings, coverage, mobility support, multicast broadcast services, and positionin

Measurement of the Tau Lepton Polarisation at LEP2

A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation Pτ of tau leptons produced in e + e − annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value Pτ=−0.164±0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV

Statistical measurement system analysis of over-the-air measurements of antenna array at 28 GHz

Abstract Next generation communication systems will use millimeter wave communication to enable higher data rates compared to Long Term Evolution (LTE) system. The coming 5G system will use antennas antenna arrays and multiple radio transceivers to compensate an excess radio signal path loss and conductive testing of an antenna array will be a challenge. Over-the-air (OTA) testing provides solution to cabling and connection problems. This paper provides an analysis of accuracy of OTA measurement at 28 GHz frequency band. A statistical measurement system analysis is used and results show that ± 0.89 dB measurement accuracy is achieved in a typical laboratory environment without an anechoic RF chamber

28 GHz Wireless Backhaul Transceiver Characterization and Radio Link Budget

Millimeter wave communication is one of the main disruptive technologies in upcoming 5G mobile networks. One of the first candidate applications, which will be commercially ready by 2020, is wireless backhaul links or wireless last mile communication. This paper provides an analysis of this use‐case from radio engineering and implementation perspectives. Furthermore, preliminary experimental results are shown for a proof‐of‐concept wireless backhaul solution developed within the EU‐KR 5GCHAMPION project, which will be showcased during the 2018 Winter Olympic Games in Korea. In this paper, we verify system level calculations and a theoretical link budget analysis with conductive and radiated over‐the‐air measurements. The results indicate that the implemented radio solution is able to achieve the target key performance indicator, namely, a 2.5 Gbps data rate on average, over a range of up to 200 m

Quality analysis of antenna reflection coefficient in massive MIMO antenna array module

Abstract Number of antennas per an antenna module will increase in upcoming 5G millimeter wave (mmW) radio products. The usage of antenna arrays compensates the increased propagation loss of a radio signal at mmW frequencies. The worst performing antenna defines the quality level MIMO antenna module. This paper presents an analysis and a relationship between the variation of the antenna resonance frequency and the reflection coefficient. A probability density function (PDF) of the antenna reflection coefficient at the specification limit is a non-linearly scaled mirrored version of the PDF of the variation of the antenna resonance. We measured the PDF of antenna reflection coefficient from manufactured prototypes and there is a good correlation between the measured and the simulated PDFs

5G mmW receiver interoperability with Wi-Fi and LTE transmissions

Abstract New interoperability problems will arise, when 5G millimeter wave (mmW) radios will be integrated into mobile devices and small cell base stations with other radios. Current LTE (Long Term Evolution) and Wi-Fi radio transceivers have not been designed, verified or specified for simultaneous operation with 5G mmW radios. Wi-Fi or LTE-LAA (Licensed Assisted Access) may introduce co-channel interference due to the harmonics falling over 5G mmW frequencies. Alternatively, the fundamental LTE or Wi-Fi transmission may block the 5G mmW receiver. This paper studies requirements for RF filtering in the LTE and Wi-Fi radios, which operate in conjunction with a 5G mmW system. Antenna isolation measurements of 5G proof-of-concept (PoC) antenna array show that mmW antenna array resonates with multiple lower frequencies due to the antenna array physical dimensions, e.g. overall module dimensions, sub-array dimensions and sub-array locations from the edges of the antenna module. Thus, lower frequency interoperability is a new optimization criterion for dimensions of mmW antenna module. Measurement results verify that a previously developed 5G mmW PoC radio and antenna module operating at 28 GHz and LTE-LAA/Wi-Fi operating at 5 GHz as well as LTE at 2.7 GHz can operate simultaneously without interference problems within the same radio unit

Study of transmitter interference to receiver at 2 GHz with high antenna port isolation

Abstract The paper presents simulated and measurement results of a planar antenna structure at 2 GHz center frequency. The antenna has two ports implemented into the same conductive body. The antenna shows measured -10 dB impedance bandwidth from 1.87 GHz to 2.18 GHz with average 41.3 dB isolation between the antenna ports over the studied frequency bandwidth. Antenna is used to measure transmitted WCDMA FDD signal leakage to the receiver with a presence of blocker signal, which is transmitted over the air. The system measurements show that the RF filtering requirements can be relaxed based on 3GPP standard by using highly isolated antenna structure. Application areas can be found at the both ends of the mobile communications system, mobile devices and small cell base stations

Wideband dual-polarized patch antenna with capacitive coupling for mm-Wave bands

Abstract This paper presents a planar wideband dual-polarized antenna structure integrated on PCB (Printed Circuit Board). The patch itself is fed by a capacitive coupling with two smaller patches, one for each polarization. Whereas the simulations predicts 24–40 GHz, -10 dB impedance bandwidth. The measured one shows 24.75–42.75 GHz bandwidth. The results are corresponding to 50% relative -10 dB impedance bandwidth. The patch antenna is on the ground plane of size 4.7 mm x 4.7 mm, and the corners of the ground plane are cut to gain better XPD (cross polarization discrimination). The manufactured prototype antenna is measured and simulated with a 50 Ω coaxial line. Simulated total efficiency and XPD are presented as a function of frequency. The total efficiency is better than -0.8 dB (83%) efficiency, whereas the simulated XPD is better than 14 dB. The simulated 3D radiation patterns are presented at 24 GHz, 32 GHz, and 40 GHz with gains of 2.8 dBi, 5.0 dBi, and 4.3 dBi, respectively