Hasil Pencarian  ::  Simpan CSV :: Kembali

"Propagation engineering in wireless communications covers the basic principles needed for understanding of radiowaves propagation for common frequency bands used in radio-communications. This book includes descriptions of new achievements and new developements in propagation models for wireless communication. The book is intended to bridge the gap between the theoretical calculations and approaches to the applied procedures needed for radio links design in a proper manner. The authors intention is to emphasize propagation engineering by giving sufficient fundamental information and then going on to explain the use of basic principles together with technical achievements in this field."

"ABSTRAKKebutuhan akan komunikasi dan transfer data berkembang pesat di beberapa dekade terakhir. Untuk mendapatkan data transfer yang lebih tinggi, perlu ditentukan peletakan antena yang tepat pada suatu sistem nirkabel. Pada tulisan ini, kami melakukan pengukuran propagasi di lingkungan iklim tropis dan pada rentang UHF ndash; S Band dengan melakukan pengukuran variasi jarak dari 10 m ndash; 100 m pada frekuensi 800 MHz, 1.8 GHz, 2.4 GHz, dan 3.3 GHz.Hasil pengukuran dibandingkan dengan nilai perhitungan dengan model-model propagasi seperti Free-Space Loss, Okumura-Hata urban dan Okumura-Hata suburban. Kemudian dianalisa untuk mengetahui pengaruh jarak terhadap kuat medan yang diperoleh. Setelah dilakukan pengukuran dan perhitungan, nilai daya yang diterima menurun seiring dengan jarak yang bertambah dan hal ini berlaku pada setiap frekuensi. Terdapat beberapa penyimpangan saat pengukuran karena pengaruh dari lingkungan sekitar. Dari kuat medan yang diperoleh tersebut dilakukan perhitungan kapasitas kanal Shannon yang kemudian dianalisa untuk mengetahui pengaruh dari kuat medan terhadap kapasitas kanal. Nilai kapasitas kanal yang diperoleh menurun seiring dengan menurunnya nilai kuat medan yang diperoleh. Hasil ini dapat digunakan untuk mengetahui kapasitas kanal maksimum dengan memperhatikan konfigurasi antena terbaik berdasarkan daya yang diterima.

---

ABSTRACTCommunication and data transfer demands are growing fast in last few decades. To obtain a higher data transfer, it is necessary to determine proper antenna placement in a wireless system. In this paper, we conduct a propagation measurements in tropical environments and UHF S Band frequency by conducting distance variation from 10 m ndash 100 m at frequency 800 MHz, 1.8 GHz, 2.4 GHz, and 3.3 GHz.The measurement results were compared with the calculation result which has been calculated using propagation models such as Free Space Loss, urban Okumura Hata and suburban Okumura Hata. The result were analyzed to determine the effect of distance to the field strength obtained. After measurement and calculation, the received power level decreases as the distances increases and this applies to every frequency. There are several deviations during measurement due to the influence of the surrounding environment. Shannon channel capacity were calculated using the field strength obtained. The result were analyzed to determine the effect of field strength to channel capacity. The value of obtained channel capacity decreases as the field strength value obtained decreases. This result can contribute to determine the maximum channel capacity by considering an optimum antenna configuration based on received power levels."

"Seiring perkembangan teknologi dan tingginya permintaan data, teknologi 5G perlu meningkatkan kapasitas, meningkatkan konektivitas, dan lebih fleksibel terhadap mobilitas pengguna. RoF berbasis gelombang milimeter mampu memberikan transmisi radio berkecepatan tinggi dengan latensi yang rendah sehingga dapat menjadi solusi untuk mencapai fleksibilitas jaringan seluler yang tinggi. Pada penelitian ini, dilakukan perancangan dan simulasi sistem Radio over Fiber berbasis gelombang milimeter dengan frekuensi radio 64 GHz menggunakan software OptiSystem 7.0 untuk memenuhi standar layanan 5G eMBB dan jaringan fronthaul 5G. Performa dari simulasi sistem dianalisis berdasarkan parameter Bit Error Rate (BER), Q Factor, dan Eye Diagram. Untuk peningkatan performa sistem, digunakan EDFA dan teknik kompensasi dispersi Fiber Bragg Grating dan Dispersion Compensating Fiber. Skenario upstream sistem telah memenuhi standar untuk layanan 5G dan jaringan fronthaul 5G dengan bit rate maksimum mencapai 5-10 Gbps. Penggunaan EDFA untuk skenario downstream sistem meningkatkan performa dengan bit rate maksimum 16 Gbps untuk panjang fiber 1 km yang memenuhi standar fronthaul D-RAN. Penggunaan FBG untuk bit rate 16 Gbps meningkatkan parameter untuk panjang fiber 4-10 km, namun tidak memenuhi standar yang dianjurkan. Penggunaan DCF meningkatkan parameter secara signifikan untuk mencapai bit rate maksimum 16 Gbps pada panjang fiber 1-10 km yang memenuhi standar fronthaul C-RAN dan D-RAN.

---

As technology develops and data demands are getting higher, 5G technology needs to increase capacity, improve connectivity, and be more flexible with user mobility. Millimeter-wave based RoF is able to provide high-speed radio transmission with low latency so that it can be a solution to achieve high flexibility of cellular networks. In this study, the design and simulation of a millimeter wave-based Radio over Fiber system with a radio frequency of 64 GHz was conducted using OptiSystem 7.0 software to meet 5G eMBB service standards and 5G fronthaul networks. The performance of the system simulation is analyzed based on the Bit Error Rate (BER), Q Factor, and Eye Diagram parameters. To improve system performance, EDFA and dispersion compensation techniques of Fiber Bragg Grating and Dispersion Compensating Fiber are used. Upstream scenario of the system meets 5G service and fronthaul network standards with peak bit rates reaching 5-10 Gbps. Using EDFA for the system’s downstream scenario improves performance with 16 Gbps peak bit rate for 1 km fiber length which meets D-RAN fronthaul standards. Using FBG with 16 Gbps bit rate increases the parameters for fiber lengths of 4-10 km, but the recommended standards are not achieved. Using DCF significantly increases the parameters to reach peak bit rate of 16 Gbps for fiber lengths of 1-10 km that meets C-RAN and D-RAN fronthaul standards."

"Two of the fastest growing sectors of communications today are mobile and Internet, both of which have had a profound effect on people's lives. The convergence between these two sectors not only presents great opportunities for the future of 'unplugged' telecommunications, but also great challenges in understanding the relative position of different technologies in this future.This book reviews the contribution of different wireless access technologies to that future and looks at the opportunities of opening up access to telecommunications systems, via application programming interfaces (APIs). The economic and regulatory issues associated with wireless communications are also discussed, with a look at the history and potential future of mobility from a user perspective."