skip to main content

Explore Research Products in the NSF-PAR

Title: Efficient Link-to-System Mappings for MU-MIMO Channel D Scenarios in 802.11ac WLANs
Results are presented from an extensive campaign of link simulations for multi-user multi-input multi-output (MU-MIMO) scenarios of 802.11ac wireless local area networks (WLAN) for use within a link-to-system mapping framework for ns-3 network simulation. As in [2], Exponential Effective SNR Mapping (EESM) is used inclusive of the impact of channel estimation, but this works extends beyond SISO to MU-MIMO. MATLAB® link simulation results using the WLAN Toolbox™ are used to generate an error rate table lookup for EESM to produce a corresponding packet error rate (PER) for use by ns-3. The simulation programs are made available to allow reproduction and extending of the baseline results.  more » « less
Award ID(s):
1836725
NSF-PAR ID:
10120304
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
WNGW 2019 Proc. Workshop on Next-Gen Wireless for ns-3
Page Range / eLocation ID:
18 to 21
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ( , WNS3 2020)
    Packet-level network simulators such as ns-3 require accurate physical (PHY) layer models for packet error rate (PER) for wideband transmission over fading wireless channels. To manage complexity and achieve practical runtimes, suitable link-to-system mappings can convert high fidelity PHY layer models for use by packet-level simulators. This work reports on two new contributions to the ns-3 Wi-Fi module, which presently only contains error models for Single Input Single Output (SISO), additive white Gaussian noise (AWGN) channels. To improve this, a complete implementation of a link-to-system mapping technique for IEEE 802.11 TGn fading channels is presented that involves a method for efficient generation of channel realizations within ns-3. The runtimes for the prior method suffers from scalability issues with increasing dimensionality of Multiple Input Multiple Output (MIMO) systems. We next propose a novel method to directly characterize the probability distribution of the"effective SNR" in link-to-system mapping. This approach is shown to require modest storage and not only reduces ns-3 runtime, it is also insensitive to growth of MIMO dimensionality. We describe the principles of this new method and provide details about its implementation, performance, and validation in ns-3. 
    more » « less
  2. ; ; ( , WNS3 '23: Proceedings of the 2023 Workshop on ns-3)
    Henderson, Thomas ; Imputato, Pasquale ; Liu, Yuchen ; Gamess, Eric (Ed.)
    Physical (PHY) layer abstraction is an effective method to reduce the runtimes compared with link simulations but still accurately characterize the link performance. As a result, PHY layer abstraction for IEEE 802.11 WLAN and 3GPP LTE/5G has been widely configured in the network simulators such as ns-3, which achieve faster system-level simulations quantifying the network performance. Since the first publicly accessible 5G NR Sidelink (SL) link simulator has been recently developed, it provides a possibility of implementing the first PHY layer abstraction on 5G NR SL. This work deploys an efficient PHY layer abstraction method (i.e., EESM-log-SGN) for 5G NR SL based on the offline NR SL link simulation. The obtained layer abstraction which is further stored in ns-3 for use aims at the common 5G NR SL scenario of OFDM unicast single layer mapping in the context of Independent and Identically Distributed (i.i.d.) frequency-selective channels. We provide details about implementation, performance, and validation. 
    more » « less
  3. ; ; ; ( , 2018 IEEE 52nd Asilomar Conference on Signals, Systems, and Computers)
    Massive multi-user multiple-input multiple-output (MU-MIMO) enables significant gains in spectral efficiency and link reliability compared to conventional, small-scale MIMO technology. In addition, linear precoding using zero forcing or Wiener filter (WF) precoding is sufficient to achieve excellent error rate performance in the massive MU-MIMO downlink. However, these methods typically require centralized processing at the base-station (BS), which causes (i) excessively high interconnect and chip input/output data rates, and (ii) high implementation complexity. We propose two feed-forward architectures and corresponding decentralized WF precoders that parallelize precoding across multiple computing fabrics, effectively mitigating the limitations of centralized approaches. To demonstrate the efficacy of our decentralized precoders, we provide implementation results on a multi-GPU system, which show that our solutions achieve throughputs in the Gbit/s regime while achieving (near-)optimal error-rate performance in the massive MU-MIMO downlink. 
    more » « less
  4. ; ; ; ( , Asilomar Conference on Signals, Systems, and Computers)
    Massive multi-user multiple-input multiple-output (MU-MIMO) enables significant gains in spectral efficiency and link reliability compared to conventional, small-scale MIMO technology. In addition, linear precoding using zero forcing or Wiener filter (WF) precoding is sufficient to achieve excellent error rate performance in the massive MU-MIMO downlink. However, these methods typically require centralized processing at the base-station (BS), which causes (i) excessively high interconnect and chip input/output data rates, and (ii) high implementation complexity. We propose two feedforward architectures and corresponding decentralized WF precoders that parallelize precoding across multiple computing fabrics, effectively mitigating the limitations of centralized approaches. To demonstrate the efficacy of our decentralized precoders, we provide implementation results on a multi-GPU system, which show that our solutions achieve throughputs in the Gbit/s regime while achieving (near-)optimal error-rate performance in the massive MU-MIMO downlink. 
    more » « less
  5. ; ; ; ( , Proc. 2019 Workshop on ns-3)
    An important challenge for ns-3 is to enable efficient performance evaluation of increasingly dense and heterogeneous networks,cognizant of cross-layer (specifically, Layers 1 & 2) interactions. In this work(a continuation of U.Washington efforts),we present improved physical layer abstractions for a key component underlying all 802.11 WLAN MAC performance evaluation-the Clear Channel Assessment(CCA) procedure central to CSMA/CA-for implementation in the ns-3 simulator. We model the preamble correlation process as typically implemented in 802.11 radio and represent the resulting probability of detection as a look-up table with a parameterized correlation threshold for different receive sensitivity strategies. Further, we also added a new carrier sense threshold adjustment mechanism to allow nodes to enable bypassing the default(and to date,fixed) -82dBm threshold. Such a capability aligns ns-3 for performance evaluation of dense networks equipped with new spatial reuse mechanisms. We demonstrate this via simulation of spatial reuse gains from dynamic sensitivity control(DSC) that are verified against IEEE 802.11ax standards group contributions. Using simulation results from a fixed rate multi-BSS network,we then identify valuable design guidelines to maximize the aggregate throughput with DSC. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email