Efficient Link-to-System Level Model for MIMO HSDPA

Abstract

To assess the performance of future mobile network technologies, system level simulations are crucial. They serve to identify whether, and to which amount, predicted link level performance gains are obtained in an entire network. In this paper, we present a computationally efficient link-to-system level model for system-level evaluations of multiple-input multipleoutput (MIMO) high-speed downlink packet access (HSDPA), including double-stream transmit antenna array (D-TxAA) as a special case. The model is based on a fairly general structure which also allows for the mapping of more than two independent streams. We base the description on the post-equalization signalto-interference-and-noise ratio (SINR) and represent it in a socalled "fading-parameter" structure, which leads to a nice split of the individual interference terms -which can be used e.g. for receiver optimization. These fading-parameters furthermore allow for a generation prior to the system level simulation itself, which reduces the computational burden significantly.

Joint throughput optimized CQI and precoding weight calculation for MIMO HSDPA

“…Besides the feedback calculation, the derived SINR expressions can also be used in system simulations to model the physical layer [8,9]. Since we validate the SINR expressions not only by physical layer HSDPA simulations but also by outdoor measurements, these expressions are very well suited to obtain accurate system simulation results and thus realistic network performance estimates.…”

“…Knowing all the above interference terms we can calculate the post equalization SINR [8,9] of the n s -th data stream at the despreader output …”

The Vienna LTE simulators - Enabling reproducibility in wireless communications research

“…Such a set-up allows for the investigation of channel tracking, channel estimation [44], synchronization [11,49], MIMO gains, AMC and feedback optimization [13], receiver structures [14] (neglecting interference and impact of the scheduling, a modeling of channel encoding and decoding [15,50], and physical layer modeling [51], which can be used for system level abstraction of the physical layer. To start a simple single-downlink simulation, run the file LTE_-sim_batch_single_downlink.m.…”

“…Thus, the physical layer has to be abstracted by simplified models capturing its essential dynamics with high accuracy at low complexity. Based on the standard approach in the literature [51,57], our simulator consists of two parts: (i) a link measurement model, and (ii) a link performance model. The link measurement model reflects the link quality, given by the UE measurement reports, and is required to carry out link adaptation and resource allocation.…”

“…The small-scale fading trace consists of the signal power and the interference power after the receive filter. The break-down into these two parts significantly reduces the computational effort since it avoids many complex multiplications required when directly working with MIMO channel matrices on system level [16,35,51].…”