Wireless Communication

Reconfigurable Intelligent Surface (RIS)

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https://www.etsi.org/technologies/reconfigurable-intelligent-surfaceshttps://www.rohde-schwarz.com/au/solutions/wireless-communications-testing/wireless-standards/6g/reconfigurable-intelligent-surfaces-ris/reconfigurable-intelligent-surfaces-ris_257043.htmlhttps://www.6gacademy.com/what-is-ris/https://wirelesspi.com/reconfigurable-intelligent-surfaces-ris-a-tutorial/ Reconfigurable Intelligent Surfaces (RIS) are physically placed to act as a bridge between the Base Station (BS) and the User Equipment (UE), particularly in scenarios where the direct path is obstructed. Physical Components of the Surface The physical layout of the surface itself is carefully engineered:

Wireless Systems – Terms

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MIMO- Multi input and multi output is wireless technology that multiplies the capcity of a radio link using multiple transmit and receive antennas.https://en.wikipedia.org/wiki/MIMO FDD (Frequency Division Duplex): A transmission mode where uplink and downlink channels operate on different frequency bands. In FDD systems, the base station typically relies on user feedback to obtain downlink CSI ... Read More

Pilots and Least Squares work

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BPSK (Binary Phase Shift Keying), a fundamental digital modulation scheme. A receiver uses a simple technique called Least Squares (LS) Channel Estimation to defeat fading and multipath interference. Wireless Channel In this simulation, the channel is designed to be intentionally difficult. It includes two major issues of digital signals: The Transmission Strategy: The Pilot Block ... Read More

pskmod, awgn, rayleigh – matlab

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Notes from – pskmod: Modulate signal using M-PSK method https://au.mathworks.com/help/comm/ref/pskmod.html The pskmod function performs M-ary Phase Shift Keying (M-PSK) modulation, converting input symbols (X) into a complex baseband signal (Y). Key Syntax data = randi([0 M-1], 1000, 1); txSig = pskmod(data, M, pi/M); Adding fading to simulation models a more complex and realistic wireless channel ... Read More

Channel Estimation

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The goal is to solve for H (the Channel) in the equation: Y=H⋅X+N (Received Signal = Channel × Transmitted Signal + Noise) [1]W. Shen, “Deep Learning-Enabled Channel Estimation for Reconfigurable Intelligent Surfaces-Aided Wireless Communications”. 1. Pilot Insertion (The “Known” Data) The receiver cannot estimate the channel using random user data because it doesn’t know what ... Read More

Channel Estimation

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https://au.mathworks.com/help/lte/ug/channel-estimation.html There are various factors that affect wireless signals. A phone may try to connect to a tower station, but multiple factors such as being in basement, being in moving train etc., the connection might be lost. This is due to the change in the channel of wireless communication system. Now the question is, can ... Read More

Learning Joint Detection, Equalization and Decoding for Short-Packet Communications – Paper Notes

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S. Dörner, J. Clausius, S. Cammerer, and S. ten Brink, “Learning Joint Detection, Equalization and Decoding for Short-Packet Communications,” IEEE Transactions on Communications, vol. 71, no. 2, pp. 837–850, Feb. 2023, doi: 10.1109/TCOMM.2022.3228648. A machine learning-based approach for joint detection, synchronization, equalization, and decoding in short-packet wireless communications, where messages must first be detected before ... Read More

Coorperative Communication

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D. K. Lee and K. M. Chugg, “A Pragmatic Approach to Cooperative Communication,” in MILCOM 2006 – 2006 IEEE Military Communications conference, Oct. 2006, pp. 1–7. doi: 10.1109/MILCOM.2006.301987. $z[k] = \sum_{n=1}^N A_{n,[k]} e^{j\Theta_n[k]} s[k] \quad = C[k] e^{j\Phi[k]} s[k]$

Terms and Terminologies in Wireless Communication

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Channel Fading: Signal experiencing fluctuations in amplitudehttps://www.geeksforgeeks.org/computer-networks/fading-in-wireless-communication/ https://www.sciencedirect.com/topics/engineering/fading-channel Signal Attenuation: Natural Loss of signal strength that occurs as a signal travels through medium or over a distance.https://en.wikipedia.org/wiki/Attenuationhttps://www.sciencedirect.com/topics/computer-science/signal-attenuation Binary Phase Shift Keying (BPSK):– represent digital data using phase; this technique -> phase shift keying (PSK)– Type of PSK -> binary phase shift keying (BPSK): use of ... Read More
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