Tero Henttonen

Nokia, Esbo, Southern Finland Province, Finland

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Publications (24)0 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a performance evaluation of Radio Frequency (RF) fingerprinting framework in heterogeneous Long Term Evolution (LTE) networks using Minimization of Drive Testing (MDT) measurements which allow automated construction of extensive RF fingerprint training databases. Fingerprint positioning was studied in heterogeneous small cell and regular macro networks using LTE cell detection performance requirements. Goal was to study how big effect the cell detection requirements have on positioning accuracy in interference limited inter-frequency small cell network deployment. The results show that RF fingerprint performance suffers degraded cell detection performance in fully loaded network deployments and results in lower dimensions of the RF signatures. However, in denser network deployments, the absolute positioning errors remain good being below the E911 emergency positioning requirements. This suggests that in dense small cell networks, MDT training databases can provide a good basis for location assisted Radio Resource Management (RRM) algorithms such as network based proximity detection.
    Communications and Networking (BlackSeaCom), 2013 First International Black Sea Conference on; 01/2013
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    ABSTRACT: In this paper we analyze the link-to-system interface for MIMO-OFDM system level simulations and propose a computationally efficient method for calculation of the effective SINR. The accuracy of the proposed fast approximation of the effective SINR is evaluated both analytically with error bound estimation and by simulated BLER performance comparison. The system level simulations in typical 3GPP LTE downlink scenario show that the proposed model is capable of accurate estimation of receiver performance for MIMO-OFDM transmission and brings up to 74% reduction in CPU simulation time.
    Information Sciences and Systems (CISS), 2012 46th Annual Conference on; 01/2012
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    ABSTRACT: In this article we study and analyze the problems related to power limitation in Long Term Evolution (LTE) uplink (UL). Power control (PC) has been specified for LTE UL to account for pathloss and slow fading variations and minimize the interference. The maximum transmission power has been limited to 23 dBm. Especially in sparse networks, this can lead to so called power limitation, where the terminals at the cell edge are forced to use less power per Physical Resource Block (PRB) than needed. Power limitation could clearly increase the packet error probability and transmission delay due to increased number of retransmissions. This may be especially problematic for Radio Resource Control (RRC) messages, e.g. handover signaling, since their reliability affects evidently on user Quality of Service (QoS). In this article we have concentrated on power boosting to improve the RRC message reliability and the performance is evaluated by means of dynamic system level simulations. It may be concluded that power boosting notably reduces the power limitation probability and thus also improves the RRC signaling reliability.
    Proceedings of the 73rd IEEE Vehicular Technology Conference, VTC Spring 2011, 15-18 May 2011, Budapest, Hungary; 01/2011
  • Niko Kolehmainen, Olli Alanen, Tero Henttonen
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    ABSTRACT: In this paper mobility performance is studied in heterogeneous networks with both macro and indoor base sta- tions. Due to abrupt changes in received signal and interference level as User Equipment (UE) enters and leaves a building with indoor Home eNodeB (HeNB) there may be additional challenges for handover compared to more homogeneous network layout. The purpose of this paper is, with dynamic system simulation tool, to evaluate the magnitude of the handover challenges and how would the system need to be configured to optimize the mobility performance. The results indicate that while general handover parameterization can be effectively utilized to avoid the most of mobility problems, cell-specific parameterization can further improve the mobility performance between eNB and HeNB. Additionally, attention should be paid to both inbound and outbound HeNB mobility due to possibly very different interference conditions in handover situations inside the building with HeNB and outdoor environment.
    Proceedings of the 73rd IEEE Vehicular Technology Conference, VTC Spring 2011, 15-18 May 2011, Budapest, Hungary; 01/2011
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    ABSTRACT: In 3GPP Rel'8 access to a Home eNodeB may be restricted to only UEs belonging to a Closed Subscriber Group (CSG). These cells are called CSG cells and a UE with CSG subscription would have an Allowed CSG List containing CSG Identities associated with the CSG cells on which the UE is allowed access. This however, can be problematic for the users located near the CSG cells, but who are not allowed to access them. The interference caused by the CSG cell can be devastating if the UE is connected to a macro cell using the same frequency. Some solutions for these interference problems have been proposed in 3GPP standardization and in this study we have evaluated the performance of different options for handling the interference issues related to mixed carrier CSG deployments. The proposals utilize different details of the LTE re-selection algorithm and suggestion on the best solution is also given.
    Vehicular Technology Conference (VTC 2010-Spring), 2010 IEEE 71st; 06/2010
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    ABSTRACT: In this paper we study the performance of idle mode mobility state detection schemes targeted for 3rd Generation Partnership Project (3GPP) Evolved UTRAN. The purpose is to compare the mobility state detection scheme specified in 3GPP Release 8 and a dual trigger scheme for 3GPP Release 9 using different User Equipment (UE) velocity conditions and cell reselection triggering sensitivity levels. A single set of cell reselection parameters may not be optimal throughout the E-UTRAN velocity range, thus both schemes provide in a way a means of using UE velocity dependent cell reselection parameters. According to the results, both schemes provide gain over a single set of cell reselection parameters. Dual trigger provides gain over Release 8 mobility state detection scheme in terms of time spent in the best cell and downlink SINR. However, this comes with a small increase in power consumption due to increased amount of cell reselections per UE.
    Wireless Pervasive Computing (ISWPC), 2010 5th IEEE International Symposium on; 06/2010
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    ABSTRACT: The purpose of this paper is benchmark the performance of voice over IP in high speed downlink packet access and in long term evolution networks. Benchmarking is conducted in homogeneous and heterogeneous scenario layouts assuming realistic propagation data generated over Tokyo map. Tools used in this paper are two fully dynamic time driven system simulators which have been used to support 3GPP standardization work. This benchmarking study provides insights to what e.g. different radio access technologies, scheduling mechanisms and receivers do for the performance of voice over IP. This paper indicated in various scenarios that long term evolution can offer higher performance for voice over IP than high speed packet access.
    Wireless Pervasive Computing (ISWPC), 2010 5th IEEE International Symposium on; 06/2010
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    ABSTRACT: In this paper we study and benchmark the performance of 3rd Generation Partnership Project (3GPP) High Speed Downlink Packet Access (HSDPA) and 3GPP Long Term Evolution (LTE) Downlink with constant bit rate type traffic. In addition a non-regular simulation scenario is considered using realistic propagation data and base station positions related to Tokyo city downtown area. HSDPA was introduced in 3GPP Release 5 and in further releases the technology has been improved with e.g. receive and transmit diversity technologies and support for higher order modulation schemes. LTE was introduced in 3GPP Release 8 with completely new physical layer and improved Radio Resource Management (RRM) functionalities. The benchmarking is performed with fully dynamic system level simulators based on detailed and commonly accepted models for e.g. mobility, propagation, call generation and fading. The results show that LTE Release 8 outperforms HSDPA Release 8 in terms of spectral efficiency and user throughput. With 8 UEs per cell and LTE MIMO about 90% of UEs are fully satisfied, while about 45% of the UEs are fully satisfied with HSDPA MIMO. This results also about 30% gain in spectral efficiency even through with LTE the network is running half empty due to uneven UE distribution in non-regular network with variable cell sizes.
    Wireless Pervasive Computing (ISWPC), 2010 5th IEEE International Symposium on; 06/2010
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    ABSTRACT: In this paper, we present a fully dynamic simulative analysis of the Downlink (DL) Voice-over-IP (VoIP) performance in 3G Long Term Evolution (LTE) with both Uplink (UL) and DL control channel constraints. In UL the Physical Uplink Control Channel (PUCCH) capacity affects the Channel Quality Indicator (CQI) resolution and in DL the Physical Downlink Control Channel (PDCCH) capacity has an impact to the amount of multiplexed users per Transmission Time Interval (TTI). The results indicate that with realistic control channel assumptions, semi-persistent packet scheduling outperforms dynamic packet scheduling.
    International Conference on Networking. 04/2010;
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    ABSTRACT: This paper proposes a potential enhancement for Discontinuous Reception (DRX) operation in Long Term Evolution (LTE) networks. In Third Generation Partnership Project's (3GPP's) Release 8 it is specified that User Equipment (UE) may be configured with DRX which controls the UE's Physical Downlink Control Channel (PDCCH) monitoring activity. By allowing discontinuous monitoring of PDCCH the UE can switch its receiver circuitry on and off for battery saving purposes. However, if UE turns its receiver circuitry off it is not capable to neither perform nor send any Channel Quality Indicator (CQI) measurements to the network prior to 'on-duration' (i.e., activity) period. This means that the Evolved Node B (e- Node B) might not have accurate CQI information and the scheduling and resource allocation could be based on outdated CQI information. To avoid reduced performance caused by the out-of-date information, this paper evaluates a scheme where a CQI preamble period is introduced prior to the actual 'on duration' time. During the preamble period UE measures the CQI and sends the measurement result to the e-Node B. The performance of the scheme is evaluated together with Voice over IP (VoIP) service. Used tool is a dynamic system level simulator which enables detailed simulation of users in multiple cells with realistic call generation, propagation, fading and mobility models. In addition to VoIP performance the UE power consumption is also evaluated with a simple model. This paper concludes that the preamble scheme can lead to improved performance in terms of VoIP capacity, and that the improvements can be achieved with acceptable trade-off in terms of battery saving opportunities
    Proceedings of the 71st IEEE Vehicular Technology Conference, VTC Spring 2010, 16-19 May 2010, Taipei, Taiwan; 01/2010
  • Alexandra Oborina, Visa Koivunen, Tero Henttonen
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    ABSTRACT: In this paper we analyze the distribution of effective Signal-to-Interference-plus-Noise-Ratio (SINR) in multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems with application to 3GPP Long Term Evolution (LTE) Downlink. The asymptotic distribution of effective SINR in case of correlated post-processed SINR is established analytically to obey normal distribution. The approximation for small number of correlated post-processed SINRs mapped to effective SINR is proposed to be the convolution of two Gamma distribution. The parameters for the Gamma distributions are analytically derived. Analytical results are verified by simulations.
    Circuits, Systems and Computers, 1977. Conference Record. 1977 11th Asilomar Conference on 01/2010;
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    ABSTRACT: The purpose of this paper is to analyze the trade-off conditions between battery saving opportunities and long term evolution network performance. To achieve this goal voice over IP with discontinuous reception is studied. Analysis is conducted with vast amount of different settings, including on duration, inactivity and discontinuous reception cycle timers. The quality of service and battery saving opportunities with discontinuous reception are evaluated with a dynamic system simulator which enables detailed simulation of multiple users and cells with realistic assumptions. This paper indicates high battery saving, i.e., increased talk-time opportunities without compromising the performance when discontinuous reception is properly adapted.
    International Conference on Networking. 01/2010;
  • A. Oborina, T. Henttonen, V. Koivunen
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    ABSTRACT: In this paper we analyze cell hearability in UTRAN Long Term Evolution (LTE) Downlink for positioning purposes. The observed time difference of arrival technique has been specified in LTE for location estimation. Successful positioning estimate requires at least three geographically diverse base stations to be detected or heard. Reference signal hearability measurements, such as Reference Signal Received Power and signal-to-interference and noise ratio of the signal from a cell, are used for detection of the cell. By means of these measurements the cell hearability is evaluated by fully dynamic time-driven system simulator. In order to mitigate the interference and improve hearability, muting of the serving cell and fractional load technique are proposed. The simulation results show improved positioning capability with proposed techniques, since all user equipments can hear the required number of geographically diverse cells.
    Signals, Systems and Computers, 2009 Conference Record of the Forty-Third Asilomar Conference on; 12/2009
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    ABSTRACT: In this paper we present different idle mode mobility state detection mechanisms targeted for 3GPP Evolved UTRAN. The purpose is to study the reliability of the mobility state detection mechanism specified in 3GPP TS 36.304 for 3GPP Release 8 in varying conditions, such as different re-selection thresholds, UE velocities and inter-site distances. Three mobility states have been defined in TS 36.304 based on occurred cell re-selections in a certain time window. According to small inter-site distance simulations, pedestrian speeds (normal mobility state) can be detected with a quite satisfactory accuracy but distinguishing the medium and high mobility states is quite challenging, since UEs are experiencing quite large variance in number of re-selections with the same UE velocities. Simulations with large inter-site distances show similar results.
    Sixth International Conference on Information Technology: New Generations, ITNG 2009, Las Vegas, Nevada, 27-29 April 2009; 01/2009
  • J. Kurjenniemi, T. Henttonen, J. Kaikkonen
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    ABSTRACT: The purpose of this paper is to evaluate the suitability of reference signal received quality (RSRQ) measurement for quality based inter-frequency handover in UTRAN long term evolution (LTE). Intra-frequency handovers in LTE are done based on reference signal received power (RSRP) measurements, which should ensure that users are always connected to the cell with the highest received power. However, in certain environments where interference causes service quality degradation for the user (which RSRP measurement is not able to detect) there might be situation where a quality-based measurement would enable better system performance. In this paper, we evaluate the success and correctness of RSRQ based inter-frequency handovers as means for preventing service degradation using dynamic system simulations. However, comparison of RSRQ and RSRP based triggering suggest that RSRQ is not able to provide robust detection of service quality degradation. Furthermore, RSRQ is found to be heavily dependent on current system loading and the measurement strategy.
    Wireless Communication Systems. 2008. ISWCS '08. IEEE International Symposium on; 11/2008
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    J. Kurjenniemi, T. Henttonen
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    ABSTRACT: In this paper we study the effect of reference signal received power (RSRP) measurement bandwidth on the accuracy of handovers and the UTRAN Long Term Evolution (LTE) system performance. In 3<sup>rd</sup> Generation Partnership Project (3GPP) it has been agreed that inter-frequency RSRP measurement requirements would be developed assuming 6 middle physical resource blocks measurement bandwidth, which has also been agreed to be used for developing intra-frequency RSRP measurement requirements. Wider handover measurement bandwidth could potentially provide better averaging against fading and thus, reduce the time required for performing inter-frequency handover measurements. These studies are conducted with fully dynamic time-driven system simulator and simulations are done with different RSRP measurement bandwidths and different filters. Based on these studies wider bandwidth provides only minor improvement in measurement accuracy and it does not clearly reduce the time required for performing measurements.
    Personal, Indoor and Mobile Radio Communications, 2008. PIMRC 2008. IEEE 19th International Symposium on; 10/2008
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    ABSTRACT: In this paper we evaluate the performance of dynamic Packet Scheduling (PS) of 3GPP UTRAN Long Term Evolution (LTE) Downlink. Packet scheduling is of utmost importance in 3G LTE, because all traffic types with different Quality of Service requirements are competing of the resources. We present a decoupled time and frequency domain packet scheduling framework for LTE downlink. Simulation results with three basic packet scheduler combinations with different amount of fairness are presented in four different 3GPP macro simulation cases to show the both extremes in tradeoff between fairness and spectral efficiency. In addition, the effect of multiuser diversity on packet scheduling performance is studied. It is shown that by dividing the packet scheduler into a time domain and a frequency domain and utilizing different algorithms in both domains, the throughput fairness between users can be effectively controlled.
    Wireless Pervasive Computing, 2008. ISWPC 2008. 3rd International Symposium on; 06/2008
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    ABSTRACT: In this paper we evaluate the dual stream multiple-input multiple-output (MIMO) performance for two rank adaptation schemes in 3GPP UTRAN long term evolution downlink. A capacity-based rank adaptation scheme as a transmission mode selection algorithm is compared to a throughput-based rank adaptation scheme by means of system level simulations run in four typical 3GPP scenarios. Additionally, the effect of mobility to system performance with multi-stream transmission is investigated in a 3GPP scenario with higher cell radius. Simulation results have been provided by using fully dynamic system level simulator. Results show that in all low-mobility (3 kmph) cases the evaluated MIMO transmission schemes provide 10iquest20% gain in terms of average and cell edge spectral efficiency. Further, we show that mobility has a clear effect on MIMO spectral efficiency and that the MIMO multiplexing gain is clearly reduced with higher user velocity. Finally, it is shown that the studied low-complexity capacity-based rank adaptation is able to reach similar performance compared to throughput-based adaptation.
    Information Sciences and Systems, 2008. CISS 2008. 42nd Annual Conference on; 04/2008
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    IJCNS. 01/2008; 1:1-9.
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    ABSTRACT: In this paper we evaluate the performance of channel quality indicator (CQI) reporting schemes in 3GPP UTRAN long term evolution (LTE) downlink (DL). In LTE, time and frequency dependent CQI is needed for DL packet scheduling (PS) and fast link adaptation (LA). Studies have indicated that frequency domain PS (FD-PS) and LA are essential techniques in improving the LTE performance, giving e.g. both cell throughput and coverage gain of around 40 % over a distributed multiplexing scheme. However, there is a tradeoff with signaling overhead related to the CQI feedback and overall LA and PS performance, which is rather overlooked in the literature. We analyze four different CQI reporting schemes with respect to system spectral efficiency and conclude that the best-M average and threshold based CQI reporting schemes seem to be the most promising in terms of the compromise between system performance and signaling overhead.
    Proceedings of the 67th IEEE Vehicular Technology Conference, VTC Spring 2008, 11-14 May 2008, Singapore; 01/2008