Experimental Research of Modulation-Coding Schemes Influence on Size of the DRM Digital Radio Broadcasting Service Area in the VHF Band. Part 2

The article presents the results of measurements of the parameters of the digital radio broadcasting DRM signal quality in the experimental zone of St. Petersburg in order to determine the influence of the transmission modes laid down in the DRM standard on the size of the service area.

An Experiment-Based Comparison between Fully Digital and Hybrid Beamforming Radio Architectures for Many-Antenna Full-Duplex Wireless Communication

Full-duplex (FD) communication in many-antenna base stations (BSs) is hampered by self-interference (SI). This is because a FD node’s transmitting signal generates significant interference to its own receiver. Recent works have shown that it is possible to reduce/eliminate this SI in fully digital many-antenna systems, e.g., through transmit beamforming by using some spatial degrees of freedom to reduce SI instead of increasing the beamforming gain. On a parallel front, hybrid beamforming has recently emerged as a radio architecture that uses multiple antennas per FR chain. This can significantly reduce the cost of the end device (e.g., BS) but may also reduce the capacity or SI reduction gains of a fully digital radio system. This is because a fully digital radio architecture can change both the amplitude and phase of the wireless signal and send different data streams from each antenna element. Our goal in this paper is to quantify the performance gap between these two radio architectures in terms of SI cancellation and system capacity, particularly in multi-user MIMO setups. To do so, we experimentally compare the performance of a state-of-the-art fully digital many antenna FD solution to a hybrid beamforming architecture and compare the corresponding performance metrics leveraging a fully programmable many-antenna testbed and collecting over-the-air wireless channel data. We show that SI cancellation through beam design on a hybrid beamforming radio architecture can achieve capacity within 16% of that of a fully digital architecture. The performance gap further shrinks with a higher number of quantization bits in the hybrid beamforming system.

A Truncated Matched Filter Method for Interrupted Sampling Repeater Jamming Suppression Based on Jamming Reconstruction

Interrupted sampling repeater jamming (ISRJ) is becoming more widely used in electronic countermeasures (ECM), thanks to the development of digital radio frequency memory (DRFM). Radar electronic counter-countermeasure (ECCM) is much more difficult when the jamming signal is coherent with the emitted signal. Due to the intermittent transmission feature of ISRJ, the energy accumulation of jamming on the matched filter shows a ‘ladder’ characteristic, whereas the real target signal is continuous. As a consequence, the time delay and distribution of the jamming slice can be obtained based on searching the truncated-matched-filter (TMF) matrix. That is composed of pulse compression (PC) results under matched filters with different lengths. Based on the above theory, this paper proposes a truncated matched filter method by the reconstruction of jamming slices to suppress ISRJ of linear frequency modulation (LFM) radars. The numerical simulations indicate the effectiveness of the proposed method and validate the theoretical analysis.

Parameter Estimation for Interrupted Sampling Repeater Jamming Based on ADMM

By repeatedly sampling, storing, and retransmitting parts of the radar signal, interrupted sampling repeater jamming (ISRJ) based on digital radio frequency memory (DRFM) can produce a train of secondary false targets symmetrical to the main false target, threatening to mislead or deceive the victim radar system. This paper proposes a computationally-effective method to estimating the parameters for ISRJ by resorting to the framework of alternating direction method of multipliers (ADMM). Firstly, the analytical form of pulse compression is derived. Then, for the purpose of estimating the parameters of ISRJ, the original problem is transformed into a nonlinear integer optimization model with respect to a window vector. On this basis, the ADMM is introduced to decompose the nonlinear integer optimization model into a series of sub-problems to estimate the width and number of ISRJ’s sample slices. Finally, the numerical simulation results show that, compared with the traditional time-frequency (TF) method, the proposed method exhibits much better performance in accuracy and stability.

Konvergensi Digital Radio Republik Indonesia Yogyakarta di Masa Pandemi Covid-19

Penelitian ini berjudul “Konvergensi Digital Radio Republik Indonesia Yogyakarta dimasa pandemi Covid-19”. Perkembangan teknologi informasi menghadirkan tantangan-tantangan baru khususnya dimasa pandemi Covid-19. Bukan hanya di indonesia, di berbagai belahan dunia juga menghadapi tantangan yaitu konvergensi media. Konvergensi Media adalah penggabungan dari beberapa jenis media dan hadir dalam bentuk digital. Perkembangan teknologi internet menimbulkan perubahan dan perkembangan dalam dunia komunikasi massa. Kemunculan new media tersebut mengubah cara masyarakat dalam mendapatkan informasi dan berita, terutama mengubah dalam sebuah newsroom di media. Penelitian ini bertujuan untuk mengetahui bagaimana praktek konvergensi kontinum di Radio Republik Indonesia (RRI) Yogyakarta pada era konvergensi media. Dalam konvergensi kontinum ini meliputi 5 (lima) tahapan yaitu Croos Promotion, Clooning, Content Sharing, Coopetition, dan Full Convergence. Metode dalam penelitian ini menggunakan metode penelitian kualitatif. Sedangkan teknik pengumpulan data yang digunakan adalah studi kepustakaan, internet, observasi, dokumentasi, dan wawancara mendalam. Hasil penelitian ini menunjukan bahwa Radio Republik Indonesia (RRI) Yogyakarta dalam praktek konvergensi kontinum sudah mencapai tahapan terakhir yaitu full convergence, dalam pengembangan produk Radio Republik Indonesia (RRI) Yogyakarta, disesuaikan dengan perkembangan teknologi dengan melakukan adaptasi dan mengedepankan karya inovatif dan kreatif.

Digital Transformation of Terrestrial Radio: An Analysis of Simulcasted Broadcasts in FM and DAB+ for a Smart and Successful Switchover

The process of digitizing radio is far from over. It is an important interdisciplinary aspect, involving Big Data and AI (Artificial Intelligence) when it comes to classifying and handling content, and an organizational challenge in the Industry 4.0 concept. There exist several methods for delivering audio signals, including terrestrial broadcasting and internet streaming. Among them, the DAB+ (digital audio broadcasting plus) system is one of the leading standards of terrestrial digital radio transmission. Compared with analog FM (frequency modulation) radio, it is more bandwidth efficient and offers greater possibilities when it comes to delivering content and forming an ensemble and multiplex. Currently, many countries worldwide, particularly European States, are still making adjustments in order to perform an efficient switchover from analog FM to digital DAB+ radio. This paper presents the current situation of the digital radio market as well as the results of a subjective quality evaluation study and questionnaire concerning broadcasting in both digital and analog techniques. It involves radio programs, transmitting both speech and music signals, simulcasted in DAB+ and FM standards. It also presents the development of the national multiplex. The results of this study may help both researchers and scientists as well as policy makers and professionals active in the field of broadcasting and electronic media and not to mention the consumption of multimedia content.

Performance of Base Stations in Railway Digital Radio Communication Networks

Base station (BS) is a terminal device of a radio communication network, while railway radio communications play an important role in ensuring safety of passenger and cargo transportation.A proposed method for calculating the performance of base stations in railway digital radio communication networks is intended to calculate for the BS the probabilities of being in certain state.BS was decomposed and such functional elements as circuit groups and a radio frequency path were identified, as well as the central module ensuring the exchange of information with elements of this BS and with other BSs. A detailed study of each element has increased accuracy of the proposed method. Following the Markov model, BS is presented as a system in which all possible states are considered. Models for BS with two and three circuit groups have been constructed. The parameters of each functional element of the model can be obtained through observation over a certain period. The solution of the system of equations for each of the models presented in the article will allow obtaining the values of the system being in a certain state. The obtained characteristics can be used to calculate the reliability of the entire radio communication network, and then to assess quality of service provided to the users of this network.Conclusions are made about the possibilities of using the obtained models when designing new railway communication networks and when calculating quality indices of existing ones. The proposed models can be applied not only to railway radio communication networks but also to mobile communication networks of commercial operators.

Sharing food, vulnerability and intimacy in a global pandemic: The digital art of the Chinese diaspora in Europe

This article examines the digital artworks created by three Chinese diaspora artists based in Europe: Berlin-based queer filmmaker Fan Popo’s short digital video Lerne Deutsch in meiner Küche (‘Learn German in my kitchen’), London-based performance artist Zeng Burong’s performance Non-Taster and London-based writer David K. S. Tse’s digital radio play The C Word. All three artworks were created in 2020 during the pandemic and all deal explicitly with the issues of anti-Asian racism and cross-cultural understanding. All these artworks also engage with issues of food and culinary practices. Through an analysis of the three artworks, I suggest that making digital art about food can serve as a creative and culturally sensitive strategy to engage with pandemic politics. Indeed, in an era of rising nationalism and international antagonism, diasporic Chinese artists have turned to seemingly mundane, apolitical and non-confrontational ways such as creating digital artworks about food to engage with the public about important social and political issues. This functions as a creative and culturally sensitive strategy to conduct social and political activism and to enhance cross-cultural understanding. It also showcases the political potential and social relevance of digital art for a pandemic and even a post-pandemic world.