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This paper describes some of the new developments of the SEAMCAT software. In particular, a detailed description of the implementation of CDMA (Code Division Multiple Access) UL (Uplink) enabling compatibility between CDMA system with single or clustered interfering systems.
Decode-and-forward relaying is a promising enhancement to current radio access networks and is now being standardized in the 3GPP work item on LTE-Advanced. Relay enhanced networks are expected to fulfill the demanding coverage and capacity requirements in a cost-efficient way. However, due to the low transmit power characteristic of relay nodes, their coverage areas will be relatively small in the...
This paper provides an assessment of 3GPP standardized LTE/LTE-A uplink power control procedures in case of a co-channel operation of different types of base stations. Especially the case of femtocell deployment with an overlaying macrocell is considered. Imperfections of the currently accepted procedures in case of such networks are pointed and a modified solution is proposed. It is shown that in...
In a loaded 1-reuse cellular network as e.g. 3GPP Long Term Evolution (LTE) the inter-cell interference limits the user bitrate for link adaptive packet data access. The cell isolation together with the link performance defines the spectrum efficiency and the achievable gain of higher order modulation or other link improving features. In this paper the cell isolation is measured as geometry factor...
Recently the number of applications requiring high throughput in 3G mobile communication networks has increased. As a result, the amount of traffic especially in urban areas has increased, requiring a high system capacity. To secure the system capacity, a sector cell configuration is generally applied. However, since the azimuth beam patterns of conventional base station antennas have moderate curve...
This paper evaluates the performance of highly loaded High Speed Uplink Packet Access (HSUPA) network with and without network wide static Interference Coordination (IC). IC alternates the priorities for user transmission periods throughout the network to achieve reduced interference levels and higher performance. A large variety of combinations including, e.g., different schedulers, cell center/edge...
Higher Order Modulation (HOM, 64-QAM) and Multiple Input Multiple Output (MIMO) transmissions are two key features introduced in the Release 7 (HSPA+) WCDMA systems to improve downlink performance. This paper focuses on the performance analysis of 64-QAM and MIMO in the WCDMA system. We describe the equalizer design for supporting these features as well as the simulation results demonstrating the...
We evaluate the performance of the uplink of a 3GPP UTRAN Long Term Evolution (LTE) system with intra-site cooperation, where different sectors belonging to the same site may cooperate with each other in order to improve the system performance. This represents an intermediate step towards general coordinated multipoint (CoMP) systems as currently under discussion for LTE-Advanced, where a cooperation...
Relaying is considered a promising cost-efficient solution in 3GPP LTE-Advanced for coverage extension and throughput enhancement. Due to compact physical characteristics and low power requirements of the relay nodes, the relay deployment has a high degree of freedom. In this paper, the impact of site planning on the backhaul performance of relay networks within the LTE-Advanced framework is investigated...
This paper examines the impact of the uplink power control and base station (BS) antenna down tilt on the system level performance in a realistic multicell three dimensional channel model. The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) adopts single carrier frequency division multiple access (SC-FDMA) as an air interface. The intra-cell interference is thus avoided but the...
Long-Term Evolution (LTE) allows operators to use new and wider spectrum and complements 3G networks with higher data rates, lower latency and a flat IP-based architecture. To further improve broadband user experience in a ubiquitous and cost effective manner, 3GPP has been working on various aspects in the framework of LTE Advanced. Since radio link performance is approaching theoretical limits with...
Coordinated multi-point transmission/reception is considered for LTE-Advanced as a tool to improve the coverage of high data rates, the cell-edge throughput and/or to increase the system throughput. Joint transmission schemes are mentioned in as an example of coordinated transmission between cells for the downlink. Here, data are transmitted simultaneously either coherently or non-coherently from...
System-level simulations of packet-based orthogonal frequency-division multiple access (OFDMA) cellular networks require a proper consideration of the channel-dependent fast fading/scheduling in order to produce meaningful results. However, generating the time and frequency selective fast fading channels and performing detailed channel-adaptive scheduling for each user in a multi-cellular system is...
Vertical handover (VHO) techniques are applied when mobile users require service continuity and a seamless roaming between heterogeneous networks. A VHO decision can be taken on the basis of physical parameters, such as the received signal strength (RSS), data rate and signal-to-interference and noise ratio (SINR). In this paper, we compare three VHO decision criterions, each of them based on different...
In this paper, the spectrum efficiency for four scenarios: baseline, cell split, fixed relay and dedicated mobile relay on vehicle are analyzed and compared in terms of unified spectrum efficiency bps/Hz/km2. The theoretical expression is derived and the capacity is calculated by numerical integration based on the parameters for 3GPP LTE-advanced system. The deployment costs for different scenarios...
The test environments for system level evaluations of IMT-A (International Mobile Telecommunications-Advanced) candidate technologies are analyzed. Compared to the evaluation criteria for previous IMT standards, the IMT-A test environments provide significantly more realistic settings for evaluating system-level performance. The models include line-of-sight probability in all scenarios, different...
This paper investigates the uplink performance of LTE-Advanced cellular networks upon relay node deployment. The uplink interference upon deploying relays is analyzed, and a resource partitioning scheme based on user grouping is proposed to mitigate the interference and improve system performance. Simulation results for the proposed resource partitioning scheme reveal that the throughput experienced...
The aim of this paper is to evaluate and compare impacts of mechanical and electrical downtilt angles of antenna systems to the downlink performance of the 3GPP Long Term Evolution (LTE) networks. Cell coverage and capacity in different macro-cellular network scenarios for various combinations of antenna parameter configurations have been studied in terms of signal to interference plus noise ratio...
Fractional frequency reuse (FFR) has been actively studied in order to reduce inter-cell interference, especially for cell edge users in current orthogonal frequency division multiple access systems. However, the best resource block (RB) allocation to the edge users is limited by conventional FFR, which has subbands consisting of contiguous RBs. In this paper, we propose a band-distributed FFR scheme...
We conduct field measurements to assess the effectiveness of the spectrum sharing method using adaptive transmit power control [2]. This investigation assumes a fixed satellite service as the victim and an IMT-Advanced system as the interferer. We evaluate the capacities achieved by adaptive transmit power control in a comparison with fixed-level transmit power control. The results show that adaptive...
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