Single-Frequency Network Terrestrial Broadcasting with 5GNR Numerology

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Single Frequency Network Broadcasting with 5GNR Numerology

This paper investigates the possibility of using 5G New Radio (5GNR) OFDM numerology in the deployment of efficient Single Frequency Networks (SFNs) for delivering TV services to user devices. The straightforward approach in the design of the physical layer for broadcasting application is based on the adoption of OFDM signalling with very long OFDM symbol and very low sub-carrier spacing (SCS). This design choice allows to dimension the Cyclic Prefix length to eliminate ISI and ICI induced by the large delay spread with a consequent overhead reduction. The 5GNR numerology is designed for unicast transmission and Cyclic Prefix lengths are not compatible with those required for large SFN networks. In this paper we consider a general receiver based on the channel shortening principle, but in the frequency domain. The receiver consists in a bank of per tone time/frequency 2D filters, possibly followed by Maximum-Likelihood (ML) trellis processing on the shortened channel. We provide promising information theoretic bound showing that the extension of 5GNR numerology to SFN is possible with very small performance loss. Even the simplest detector architecture that does not employ trellis processing provides throughput competitive with those that can be obtained with smaller SCS. We provide end to end simulation results with practical modulation and LDPC encoder confirming that the results predicted by the bounds can be closely matched in practice

Single-Frequency Network Terrestrial Broadcasting with 5GNR Numerology Using Recurrent Neural Network

We explore the feasibility of Terrestrial Broadcasting in a Single-Frequency Network (SFN) with standard 5G New Radio (5GNR) numerology designed for uni-cast transmission. Instead of the classical OFDM symbol-by-symbol detector scheme or a more complex equalization technique, we designed a Recurrent-Neural-Network (RNN)-based detector that replaces the channel estimation and equalization blocks. The RNN is a bidirectional Long Short-Term Memory (bi-LSTM) that computes the log-likelihood ratios delivered to the LDPC decoder starting from the received symbols affected by strong intersymbol/intercarrier interference (ISI/ICI) on time-varying channels. To simplify the RNN receiver and reduce the system overhead, pilot and data signals in our proposed scheme are superimposed instead of interspersed. We describe the parameter optimization of the RNN and provide end-to-end simulation results, comparing them with those of a classical system, where the OFDM waveform is specifically designed for Terrestrial Broadcasting. We show that the system outperforms classical receivers, especially in challenging scenarios associated with large intersite distance and large mobility. We also provide evidence of the robustness of the designed RNN receiver, showing that an RNN receiver trained on a single signal-to-noise ratio and user velocity performs efficiently also in a large range of scenarios with different signal-to-noise ratios and velocities

The Use of Chinese Herbal Drugs in Islamic Medicine

This paper investigates some of the ways that Chinese medicine has been transferred to the Western world and to Islamic territories. During the Golden Age of Islam (8th to 13th century CE), the herbal drug trade promoted significant commercial and scientific exchange between China and the Muslim world. Chinese herbal drugs have been described by medieval Muslim medical scholars such as Tabari (870 CE), Rhazes (925 CE), Haly Abbas (982 CE), Avicenna (1037 CE) and Jurjani (1137 CE). The term al-sin (the Arabic word for China) is used 46 times in Avicenna’s Canon of Medicine in reference to herbal drugs imported from China. Cinnamon (dar sini; “Chinese herb”), wild ginger (asaron), rhubarb (rivand-e sini), nutmeg (basbasa), incense tree wood (ood), cubeb (kababe) and sandalwood (sandal) were the most frequently mentioned Chinese herbs in Islamic medical books. There are also multiple similarities between the clinical uses of these herbs in both medical systems. It appears that Chinese herbal drugs were a major component of the exchange of goods and knowledge between China and the Islamic and later to the Western world amid this era