Showing papers by "Aarno Parssinen published in 2016"

5G CHAMPION - Rolling out 5G in 2018

Abstract: The 5G CHAMPION Consortium will provide the first fully integrated and operational 5G prototype in 2018 - this effort is a major leap ahead compared to existing punctual technology trials, such as, e.g., Proof-of-Concept platforms focusing on mmWave communication in specific bands, etc. This paper describes the overall set-up including a synergetic combination of technologies such as beamforming based mmWave a Satellite service provisioning, virtualized infrastructure, software reconfiguration across the entire stack, accurate positioning and high-speed solutions. The key enablers are described in detail and related efforts in standards and regulation organizations are discussed.

Real time adaptive RF and digital self-interference cancellation for full-duplex transceivers

Abstract: The challenges with full-duplex (FD) transceiver implementation and transmission in small area radio communication systems are considered. The main challenge in the FD transceiver design is the self-interference (SI). Analog and digital SI cancellation is used for SI mitigation. Analog SI isolation is performed at radio frequency (RF) by utilizing an antenna design based on the characteristic modes theory and using active cancellation principle. Phase and attenuation values of the active cancellation signal path are tuned using a variable-step steepest descent algorithm while transmitting a data signal to a distant node in foil-duplex mode. After the tuning, the SI isolation at RF processing is 90 dB. The remaining SI is then cancelled at the baseband processing for which the an estimate of the SI channel is needed. The SI channel estimation is done in full-duplex mode. Because the receiver has full knowledge of the transmitted signal, no extra pilots are used for the SI cancellation.

Polarization based measurement system for analysis of GNSS multipath signals

Abstract: In this paper, the principle of a polarization-based measurement system intended for the data recording of the Global Navigation Satellite System (GNSS) signals is described. The measurement arrangement includes left- and right hand circular polarized antennas with separate satellite RF recorders for both polarizations. Based on the recorded data for different antenna polarizations the Line-Of-Sight (LOS) and the reflected Non-Line-Of-Sight (NLOS) signal components can be analyzed in order to generate a three-dimensional channel model. Initial field measurements are performed for a route of one kilometer in a university campus area. The initial recorded data include digitized RF signals for all visible Global Positioning System (GPS) satellites, the National Marine Electronics Association (NMEA) data, video recording of the environment and reference velocity from a separate speed sensor. In this paper, the preliminary analysis of the recorded data is presented. Based on the recorded data it is concluded that the polarization based measurement system is able to separate LOS and NLOS signal components thus enabling first steps toward the three-dimensional GNSS channel model development.

RF system requirement analysis and simulation methods towards 5G radios using massive MIMO

Abstract: Methods of performing RF system requirement analysis towards 5th generation massive multiple-input multiple-output system are described. For the system analysis, digital signal processing is abstracted to minimum SNR requirement definitions and RF system SNR is described based on realistic but highly simplified transmitter and receiver performance related to output and input power levels, respectively. In addition, a simple link adaptation model is created for dynamic simulation tasks. As the contribution of antenna array is seen to become necessity in cm- and mm-wave bands for 5G systems, we show ways to include antenna modelling in system analysis. By using these analysis methods, we have generated a link level simulator that can be used for system analysis using different abstractions of antennas. Finally, it is shown that even simple RF models need to have certain implementation related details in order to provide good accuracy in link budget and operation range analysis.

Analysis of the measured RHCP and LHCP GNSS signals in multipath environment

Abstract: The performance evaluation of Global Navigation Satellite System (GNSS) device in 3D laboratory measurement environment is gaining increasing importance. Even though GNSS is a mature technology the 3D channel model to be implemented in laboratory environment does not exist due to the challenges encountered in creating controllable and repeatable multipath conditions. This research work is a first step toward the one solution of these problems. In this paper, the GNSS data set recorded with the polarization based measurement system is analyzed. Both Right Hand Circularly Polarized (RHCP) and Left Hand Circularly Polarized (LHCP) antennas are employed so that direct and reflected signals can be acquired simultaneously. The goal of the study is to investigate the characteristics of polarization based reflections, path length of delayed multipath signal, position error, coverage efficiency (mean number of tracked satellites), and the impact of satellite elevation angle on received Signal-to-Noise Ratio (SNR) for a typical multipath environment. Results show that satellite elevation angle, and multipath propagation affect both the position precision measured by the receiver and SNR. Additionally, presented results will serve as basis for the development of 3D GNSS channel model to work for both static and dynamic environments.

Downlink output power requirements with an experimental-based indoor LOS/NLOS MIMO channel models at 10 GHz to provide 10 Gbit/s

Abstract: The present paper studies link output power requirements per connection in order to provide 10 Gbit/s or more with included MIMO beam-specific path gains for spatially multiplexed data streams. Time-duplexing orthogonal frequency-division multiplexing 5G system is examined. System performance is considered in line-of-sight (LOS) and non-LOS channels. This work utilizes RF modelling method where digital signal processing is abstracted to minimum SNR requirement definitions and RF system SNR described based on transmitter and receiver performance related to output and input power levels. As the output of this work represents indoor link RF output power requirements, the results can be utilized in several research directions; e.g., providing dynamic range requirements for a power amplifier concept and for RF transceiver architecture optimization in terms of complexity and power consumption.

Providing 10 Gbit/s in Downlink to a Mobile Terminal with Practical Array Design Beamforming Aspects by Using Orthogonal MIMO Beams

Abstract: Orthogonal MIMO beam directions for spatially multiplexed data streams (SMDSs) and terminal array limitations with a steering angle are studied in this paper. As delivering SMDS for large distances is challenging, the research work studies a short-range indoor environment with line-of-sight (LOS) & non-LOS MIMO channel models for time-division duplex orthogonal frequency-division multiplexing 5G system. Radio frequency (RF) modelling method is utilized for link budget analysis where digital signal processing is abstracted to the minimum signal-to-noise ratio (SNR) requirements and RF system SNR described based on transmitter and receiver performance related to output and input power levels. By limiting a terminal to six array elements at 10 GHz, it is shown that channel dynamic range, e.g., in LOS can even exceed some 45 dB between the best and worst eigen value-based beams. For some users, beam angle-of-arrivals were observed to vary even 100 degrees. Mobile array steering range was shown to cause fundamental restrictions to capture SMDSs from wide beam angles with sufficient array gain. Achieved user data rates and power consumption are demonstrated at the end of this paper.

The effects of non-linearity in spectrum sensing receivers

Abstract: This paper analyses the effects of receiver non-linearity on the performance of the most commonly utilized signal detectors in cognitive radio systems. The analysis covers both self-modulation products of a single orthogonal frequency-division multiplexing (OFDM) signal and intermodulation (IM) products of two OFDM signals, and also their contribution to the probability of false detections. As a result, this work presents the linearity requirements for the spectrum sensor receiver front-end as a function of the sensitivity of the signal detector. Furthermore, we show that the cyclostationary feature detectors are more robust than the energy detectors against IM products of multiple interferers. Theoretical results are verified in measurements with a cyclostationary feature detector using digital video broadcasting – terrestrial (DVB-T) signals as an example.