Model Kanal 5G dengan Pengaruh Kelembapan pada Frekuensi 3,3 GHz dan Bandwidth 99 MHz Berbasis Convolutional Codes

ABSTRAKGenerasi telekomunikasi kelima (5G) diterapkan pada 2021 dengan frekuensi tinggi yang menyebabkan redaman yang besar dibandingkan pita sub-1 GHz. Penelitian ini mengkaji sistem 5G dengan frekuensi operasi 3,3 GHz dan bandwidth 99 MHz berdasarkan spesifikasi 5G dari Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) numerologi μ = 1 menggunakan parameter lingkungan yang diukur secara langsung di kota Bandung. Penelitian ini menemukan bahwa model kanal 5G dengan pengaruh kelembapan maksimum memiliki power delay profile (PDP) 9 path dengan nilai daya yang lebih kecil dan outage performances (𝑅>𝐶) yang lebih buruk dengan gap sebesar 0,3 dB dibandingkan dengan pengaruh kelembapan minimum. Hasil penelitian menunjukkan bahwa penggunaan convolutional codes dapat membantu menghemat Signal to Noise Ratio (SNR) dengan gap sebesar 3 dB. Hasil dari penelitian ini diharapkan dapat memberikan kontribusi bagi perkembangan komunikasi nirkabel 5G di Indonesia.Kata kunci: 5G, model kanal, convolutional codes, PDP, FER, BER. ABSTRACTThe fifth generation of telecommunications (5G) implemented in 2021, where high frequency which causes a large attenuation compared to the sub-1 GHz band. This research examines a 5G system with an operating frequency of 3.3 GHz and a bandwidth of 99 MHz based on the 5G specification of the Cyclic Prefix - Orthogonal Frequency Division Multiplexing (CP-OFDM) numerology μ = 1 using environmental parameters measured directly in Bandung, Indonesia. This research shows that the 5G channel model under maximum humidity has a 9 power delay profile (PDP) with a smaller power value and worse outage performances (𝑅>𝐶) with a gap of 0.3 dB compared to the effect of minimum humidity. The results showed that the use of convolutional codes can save the Signal to Noise Ratio (SNR) with gap of 3 dB. The results of this research are expected to contribute to the development of 5G wireless communications in Indonesia.Keywords: 5G, channel model, convolutional codes, PDP, FER, BER.

Analysis of cyclic prefix length effect on ISI limitation in OFDM system over a Rayleigh-fading multipath

<span>In this work, the influence of the cyclic prefix on the performance of the OFDM system is studied. We worked out an OFDM transceiver using a 16 QAM modulation scheme, a comparison of the BER for various lengths of the cyclic prefix has been achieved, and the influence of the noise introduced in the channel has been highlighted, for both a Gaussian and Rayleigh noise. The simulation was carried out on MATLAB where the curves of the BER for various lengths of the cyclic prefix are given and compared. We also adopted as a metric the QAM constellation to show the dispersion of the carriers as a consequence of the transmission channel, the mitigation of this effect by the CP is noticeable.</span>

Analog hardware trojan design and detection in OFDM based wireless cryptographic ICs

Due to Hardware Trojan (HT), trustworthiness of Integrated Circuit (IC) supply chain is a burning issue in Semiconductor Industry nowadays. Over the last decade, extensive research has been carried on HT detection methods for digital circuits. However, the HT issue remains largely unexplored in the domain of Analog Mixed Signal (AMS)/ RF circuit where it is now an appealing target for the attackers. The increasing popularity of Orthogonal Frequency Division Multiplexing (OFDM) based wireless cryptographic ICs in modern communication systems makes it a lucrative target for HT-based attacks which could have a devastating impact on data security. This paper presents a trigger-based Hardware Trojan Threat model that exploits the extended cyclic prefix (ECP) property of the OFDM communication scheme to leak the secret encryption key over low noise Additive White Gaussian Channel (AWGN) and developed a Cyclic Prefix (CP) checker based detection mechanism named “SENTRY” to detect such trojans once it is triggered.

PHY, MAC, and RLC Layer Based Estimation of Optimal Cyclic Prefix Length

This work is motivated by growing evidence that the standard Cyclic Prefix (CP) length, adopted in the Long Term Evolution (LTE) physical layer (PHY) specifications, is oversized in propagation environments ranging from indoor to typical urban. Although this ostensibly seems to be addressed by 5G New Radio (NR) numerology, its scalable CP length reduction is proportionally tracked by the OFDM symbol length, which preserves the relative CP overhead of LTE. Furthermore, some simple means to optimize fixed or introduce adaptive CP length arose from either simulations or models taking into account only the bit-oriented PHY transmission performance. On the contrary, in the novel crosslayer analytical model proposed here, the closed-form expression for the optimal CP length is derived such as to minimize the effective average codeblock length, by also considering the error recovery retransmissions through the layers above PHY—the Medium Access Control (MAC) and the Radio Link Control (RLC), in particular. It turns out that, for given protective coding, the optimal CP length is determined by the appropriate rms delay spread of the channel power delay profile part remaining outside the CP span. The optimal CP length values are found to be significantly lower than the corresponding industry-standard ones, which unveils the potential for improving the net throughput.

Wavelet OFDM for Power Line Communication

Power Line Communication (PLC) system offers cheaper mode of signal communication facilities. In fast Fourier transform (FFT) based multicarrier PLC system, a cyclic prefix (CP) of the same length of the channel impulse response is added to each symbol in order to transmit data. As a result, there is always an inherent wastage of bandwidth and resources. This research presents a wavelet transform based orthogonal frequency division multiplexing (WTOFDM) approach that eliminates the need for these cyclic prefix and improves the efficiency of the PLC transmission. The presented PLC model is designed for faster and efficient transmission over the power line. The obtained results indicate that the proposed approach enhances the transmission throughput; provides better performance for impulsive noise, and increases the efficiency of the PLC system as a whole. In the end a performance comparison of different wavelet techniques have also been incorporated.

Wavelet OFDM for Power Line Communication

Power Line Communication (PLC) system offers cheaper mode of signal communication facilities. In fast Fourier transform (FFT) based multicarrier PLC system, a cyclic prefix (CP) of the same length of the channel impulse response is added to each symbol in order to transmit data. As a result, there is always an inherent wastage of bandwidth and resources. This research presents a wavelet transform based orthogonal frequency division multiplexing (WTOFDM) approach that eliminates the need for these cyclic prefix and improves the efficiency of the PLC transmission. The presented PLC model is designed for faster and efficient transmission over the power line. The obtained results indicate that the proposed approach enhances the transmission throughput; provides better performance for impulsive noise, and increases the efficiency of the PLC system as a whole. In the end a performance comparison of different wavelet techniques have also been incorporated.

FILTER BANK MULTICARRIER (FBMC) UNTUK 5G

Saat ini, teknologi pada bidang telekomunikasi berkembang dengan pesat. Pengguna telekomunikasi membutuhkan teknologi komunikasi yang cepat dengan bandwidth yang lebih lebar. Oleh karena itu dikembangkanlah Filter Bank Multi Carrier/Offset Quadrature Amplitude Modulation yang merupakan teknologi kandidat modulasi yang akan digunakan pada 5G. Filter Bank Multi Carrier/Offset Quadrature Amplitude Modulation (FMBC/OQAM) merupakan perkembangan dari Orthogonal Frequency Division Multiplexing (OFDM) yang dimodifikasi dengan menggunakan filter untuk mengurangi noise. OFDM menggunakan teknik multiplexing yang membagi bandwith menjadi beberapa frekuensi sub-carrier. Tetapi OFDM memiliki kelemahan yaitu memerlukan Cyclic Prefix (CP) untuk mengatasi Intersymbol Interference (ISI) serta Intercarrier Interference (ICI). Dengan menggunakan Filter berdasarkan Lembaga Physical layer for dynamic spectrum access and cognitive radio (PHYDYAS) ,lebar bandwith yang bertambah akibat Cyclic prefix akan dapat dikurangi Hasil yang dicapai dalam penelitian ini adalah FBMC berhasil diterapkan dan data yang dikirim sama dengan data yang diterima.