Traditional modulation methods adopted by space agencies for transmit- ting telecommand and telemetry data have incorporated subcarriers as a sim- ple means of separating different data types as well ensuring no overlap between the radio frequency (RF) carrier and the modulated data’s frequency spectra.
標簽: Bandwidth-Efficient Modulation Digital
上傳時間: 2020-05-26
上傳用戶:shancjb
The idea of the book was born during the time when the second generation cellular system was looming on the horizon.At that time ,the world was divided into three distinct camps as far as looking for a standard: Europe North America and Japan.
標簽: Designing Cellular Systems Mobile Radio
上傳時間: 2020-05-26
上傳用戶:shancjb
The aim of this book, the first of two volumes, is to present selected research that has been undertaken under COST Action IC0902 ‘‘Cognitive Radio and Net- working for Cooperative Coexistence of Heterogeneous Wireless Networks’’ (http://newyork.ing.uniroma1.it/IC0902/). COST (European Cooperation in Sci- ence and Technology) is one of the longest-running European frameworks sup- porting cooperation among scientists and researchers across Europe.
上傳時間: 2020-05-26
上傳用戶:shancjb
The idea of writing this book entitled “Cognitive Networked Sensing and Big Data” started with the plan to write a briefing book on wireless distributed computing and cognitive sensing. During our research on large-scale cognitive radio network (and its experimental testbed), we realized that big data played a central role. As a result, the book project reflects this paradigm shift. In the context, sensing roughly is equivalent to “measurement.”
標簽: Cognitive Networked Sensing Data Big and
上傳時間: 2020-05-26
上傳用戶:shancjb
Today’s wireless services have come a long way since the roll out of the conventional voice-centric cellular systems. The demand for wireless access in voice and high rate data multi-media applications has been increasing. New generation wireless communication systems are aimed at accommodating this demand through better resource management and improved transmission technologies.
標簽: Radio Cognitive Software Defined
上傳時間: 2020-05-26
上傳用戶:shancjb
Wireless technology has been evolving at a breakneck speed. The total number of cell-phones in use (as of 2011) was over 6 billion for a 7 billion world population [1] constituting 87% of the world population. Additionally, with user convenience be- coming paramount, more and more functions are being implemented wirelessly.
標簽: Front-Ends Cognitive Receiver Radio
上傳時間: 2020-05-26
上傳用戶:shancjb
Cognitive radio has emerged as a promising technology for maximizing the utiliza- tion of the limited radio bandwidth while accommodating the increasing amount of services and applications in wireless networks. A cognitive radio (CR) transceiver is able to adapt to the dynamic radio environment and the network parameters to maximize the utilization of the limited radio resources while providing flexibility in wireless access. The key features of a CR transceiver are awareness of the radio envi- ronment (in terms of spectrum usage, power spectral density of transmitted/received signals, wireless protocol signaling) and intelligence.
標簽: Cognitive Wireless Network
上傳時間: 2020-05-26
上傳用戶:shancjb
The capability of radio waves to provide almost instantaneous distant communications without interconnecting wires was a major factor in the explosive growth of communica- tions during the 20th century. With the dawn of the 21st century, the future for communi- cations systems seems limitless. The invention of the vacuum tube made radio a practical and affordable communications medium.
上傳時間: 2020-05-26
上傳用戶:shancjb
The new digital radio system DAB (Digital Audio Broadcasting, nowadays often called Digital Radio) is a very innovative and universal multimedia broadcast system which will replace the existing AM and FM audio broadcast services in many parts of the world in the future. It was developed in the 1990s by the Eureka 147/DAB project. DAB is very well suited for mobile reception and provides very high robustness against multipath reception. It allows use of single frequency networks (SFNs) for high frequency efficiency.
標簽: Broadcasting Principles Digital Audio
上傳時間: 2020-05-27
上傳用戶:shancjb
The design and manufacturing of wireless radio frequency (RF) transceivers has developed rapidly in recent ten yeas due to rapid development of RF integrated circuits and the evolution of high-speed digital signal processors (DSP). Such high speed signal processors, in conjunction with the development of high resolution analog to digital converters and digital to analog converters, has made it possible for RF designers to digitize higher intermediate frequencies, thus reducing the RF section and enhancing the overall performance of the RF section.
標簽: Transceivers Wireless Digital
上傳時間: 2020-05-27
上傳用戶:shancjb