Mobile operators must continuously pursue cost‐ effective and efficient solutions to meet the high data demand requirements of their subscribers. Limited spectrum allocations and non‐contiguous spectrum blocks continue to pose challenges for mobile operators supporting large data uploads and downloads across their networks. With the increase in video and social media content, the challenges have increased exponentially.
標簽： qorvo-carrier-aggregation-fundame ntals
上傳時間： 2020-05-31
上傳用戶：shancjb
Cognitive radios have become a vital solution that allows sharing of the scarce frequency spectrum available for wireless systems. It has been demonstrated that it can be used for future wireless systems as well as integrated into 4G/5G wireless systems. Although there is a great amount of literature in the design of cognitive radios from a system and networking point of view, there has been very limited available literature detailing the circuit implementation of such systems. Our textbook, Radio Frequency Integrated Circuit Design for Cognitive Radios, is the first book to fill a disconnect in the literature between Cognitive Radio systems and a detailed account of the circuit implementation and architectures required to implement such systems. In addition, this book describes several novel concepts that advance state-of-the-art cognitive radio systems.
標簽： Cognitive Systems Design Radio RFIC for
上傳時間： 2020-06-01
上傳用戶：shancjb
This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation, the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.
標簽： Telecommunications Processing Signal for
上傳時間： 2020-06-01
上傳用戶：shancjb
The radio spectrum is one of the most precious resources which must be managed to ensure efficient access for the wireless communication services which use it. The allocation and management of spectrum are administered by the regulatory authorities. Traditionally, spectrum allocation is carried out exclusively of its use in large geographic areas and assigning frequency bands to specific users or service providers is proved to be inefficient. Recently, substantial knowledge about dynamic spectrum access scheme has been accumulated to enable efficient spectrum sharing.
標簽： Management Spectrum Access and
上傳時間： 2020-06-01
上傳用戶：shancjb
When 3GPP started standardizing the IMS a few years ago, most analysts expected the number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly after that). While those predictions have proven to be too aggressive owing to a number of upheavals hitting the ICT (Information and Communications Technologies) sector, we are now seeing more and more commercial IMS-based service offerings in the market. At the time of writing (May 2008), there are over 30 commercial IMS networks running live traffic, addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally. In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS contracts have been awarded to all IMS manufacturers. The number of IMS users will grow substantially as these awarded contracts are launched commercially. At the same time, the number of IMS users in presently deployed networks is steadily increasing as new services are introduced and operators running these networks migrate their non-IMS users to their IMS networks.
標簽： Multimedia Subsystem The IMS 3G IP
上傳時間： 2020-06-01
上傳用戶：shancjb
The wide deployment of wireless networks and mobile technologies, along with the significant increase in the number of mobile device users, have created a very strong demand on various wireless-based, mobile-based software application systems and enabling technologies. This not only provides many new business opportunities and challenges to wireless and networking service providers, mobile technology ven- dors, and software industry and solution integrators, butalso changes and enhances people’s lives in many areas, including communications, information sharing and exchange, commerce, home environment, education, and entertainment. Business organizations and government agencies face new pressure fortechnology updatesto upgrade their networking infrastructures with wireless connectivity to enhance enterprise-oriented systems and solutions.
標簽： Wireless-Based Software Systems
上傳時間： 2020-06-01
上傳用戶：shancjb
The Home Gateway Initiative (HGI) is a non-profit making organization which publishes guidelines, requirements documents, white papers, vision papers, test plans and other documents concerning broadband equipment and services which are deployed in the home.
標簽： Evaluation Discussion Framework Document KPI
上傳時間： 2020-06-06
上傳用戶：shancjb
RFID (radio-frequency identification) is the use of a wireless non-contact system that uses radio-frequencyelectromagnetic fields to transfer datafrom a tag attached to an object, for the purposes of automatic identification and tracking [38]. The basic technologies for RFID have been around for a long time. Its root can be traced back to an espionage device designed in 1945 by Leon Theremin of the Soviet Union,whichretransmittedincidentradiowaves modulatedwith audioinformation. After decades of development, RFID systems have gain more and more attention from both the research community and the industry.
標簽： Infrastructure RFID as an
上傳時間： 2020-06-08
上傳用戶：shancjb
This book is about the Arduino microcontroller and the Arduino concept. The visionary ArduinoteamofMassimoBanzi,DavidCuartielles,TomIgoe,GianlucaMartino,andDavidMellis launchedanewinnovationinmicrocontrollerhardwarein2005,theconceptofopensourcehardware. There approach was to openly share details of microcontroller-based hardware design platforms to stimulate the sharing of ideas and innovation.This concept has been popular in the software world for many years.
標簽： Microcontroller Processing Arduino
上傳時間： 2020-06-09
上傳用戶：shancjb
This book is about the Arduino microcontroller and the Arduino concept. The visionary ArduinoteamofMassimoBanzi,DavidCuartielles,TomIgoe,GianlucaMartino,andDavidMellis launchedanewinnovationinmicrocontrollerhardwarein2005,theconceptofopensourcehardware. There approach was to openly share details of microcontroller-based hardware design platforms to stimulate the sharing of ideas and innovation.This concept has been popular in the software world for many years.
標簽： Microcontroller Processing Everyone Arduino Part for
上傳時間： 2020-06-09
上傳用戶：shancjb
