IMION - Interference Mitigation In OFDM Networks
IMICT FEI STU
IMICT FEI STU
Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project
No. 09I03-03-V04-00259.
Palenik T., Szitkey V. Interference in OFDM Systems and Networks. International Journal Information Technology Applications (ITA) Vol. 13, Nr. 2, Dec. 2024. ISSN: 2453-7497.
Fulltext: https://arxiv.org/abs/2503.04216
Journal home: https://www.itajournal.com/index.php/ita
Abstract:
In this paper we present an overview of various kinds of interference, that arise in the Orthogonal Frequency-Domain Multiplexing (OFDM)-based digital communications systems at the physical layer. Inter-symbol, inter-block, inter-carrier interference types are described in detail, valid for any OFDM transmission, along with Inter-cell interference specific to cellular networks. A survey of various communication disruptions techniques is presented – primarily focusing on intentional interference – jamming. Furthermore, we present a survey of modulation techniques that expand on the OFDM and may be considered viable candidates for modulation in the future 6G cellular networks.
Available on GitHub onder GPL 3.0: https://github.com/talenik/OFDMtoolkit
Implements simulations of OFDM transmission within AWGN or Rayleigh-fading channel
QAM, uncoded or LDPC - encoded,
Jamming of OFDM pilot signal results obtained by the toolkit published in:
Palenik. T., Szitkey V. Intelligent jamming of an OFDM system with AIassisted LDPC decoder implementation. In proc. ELITECH '25, 27th Conf, of Doctoral Students, 28th May 2025, FEI STU Bratislava, Slovakia
Conference home: https://www.fei.stuba.sk/buxus/docs/Elitech/2025/Sprava_ELITECH_2025.pdf
Abstract:
In this paper we present our MATLAB framework for simulation of Orthogonal Frequency Division Multiplexing (OFDM) digital communications system operation and its usage for evaluating the effects that potential jammers have on the error performance of data transmission. We evaluate two jamming scenarios – a classical wideband jammer affecting all the OFDM subcarriers, and an intelligent jammer, that focuses on a critical weak spot – the pilot signals present in OFDM in order to equalize the distortion introduced by a multipath channel propagation in the context of Rayleigh channel. The overview of practical usage of OFDM in current systems is given along with directions for potential evolution and trends for future 6G systems. Furthermore, we present our experiences with our AI-assisted implementation of modern Low-Density-Parity-Check (LDPC) Error Correction Code (ECC), focusing on the IEEE 802.11ax-defined LDPC control matrices and practical Min-Sum decoder algorithm.
Palenik. T., Szitkey V. Intelligent jamming of an OFDM system with AIassisted LDPC decoder implementation.
In proc. ELITECH '25, 27th Conf, of Doctoral Students, 28th May 2025, FEI STU Bratislava, Slovakia
Conference home: https://www.fei.stuba.sk/buxus/docs/Elitech/2025/Sprava_ELITECH_2025.pdf
Abstract:
Palenik T., Szitkey V. Detection of jamming in an LDPC-coded OFDM transmission
Submitted to International scientific conference IEEE ANTS New Delhy India. Pending acceptance information. Not published yet.
Conference home home: https://ants2025.ieee-ants.org/
Abstract:
In this paper we present the design of our simple OFDM jamming detection method, usable for detecting several jamming attacks, including repeat-back-jamming like designs, previously deemed undetectable. This method is dependent on the presence of a compatible ECC, such as LDPC, as it uses its iterative soft-decoder statistics as its basis. The method is evaluated using our free and open source MATLAB OFDM+LDPC toolkit. Furthermore, the feasibility of the jamming is evaluated by measurements in real, over-the-air radio transmission scenario, with a SDR transmitter, receiver, and jammer implementation using USRP frontends. Measurements of the jammer latency, detrimental to the success of this attack, are presented.
Hardware:
three powerfull PCs connected to SDR signal processors USRP (transmitter (TX), receiver (RX), jammer (JAM))
GPS sychronized precision clock
Picoscope digital oscillator
Two PCs with connected USRPs N210 implement OFDM TX and RX:
One PC implements the jammer:
Sowtware:
GNU Radio Companion testbed implementation implementing OFDM TX, RX, JAM TODO zip file
MATLAB for simulations and measurement data postprocessing
GRC Simulations download here
Calibration report: download excel tables
OFDM TX implemented in GNU Radio Companion:
OFDM RX implemented in GNU Radio Companion:
Dataset 1: OFDM TX: GRC file, samples captures for 4QAM and 16QAM Download here.* ( 18 GiB.)
Dataset 2: OFDM RX: GRC file, samples captures for 4QAM and 16QAM Download here.* (25 GiB).
Dataset3: OFDM RBJ latency measurements Download samples data file. Carefull: 9 GiB.
*Carefull, contains directory structure. Download individual files separately. If you download whole folder, google drive will rewrite file names.
These datasets are published under the Creative Commons CC BY-SA license, allowing to remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms. [ As defined by: https://creativecommons.org/licenses/by-sa/4.0/ ]