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.
标签： Transceivers Wireless Digital
上传时间： 2020-05-27
上传用户：shancjb
The continued reduction of integrated circuit feature sizes and commensurate improvements in device performance are fueling the progress to higher functionality and new application areas. For example, over the last 15 years, the performance of microprocessors has increased 1000 times. Analog circuit performance has also improved, albeit at a slower pace. For example, over the same period the speed/resolution figure-of-merit of analog-to-digital converters improved by only a factor 10.
标签： Digitally Assisted Pipeline ADCs
上传时间： 2020-05-27
上传用户：shancjb
Wireless Fidelity (Wi-Fi) networks have become mainstream over the last few years. What started out as cable replacement for static desktops in indoor networks has been extended to fully mobile broadband applications involving moving vehicles, high-speed trains, and even airplanes.
标签： Technologies Emerging Wireless Theory LANs in
上传时间： 2020-05-27
上传用户：shancjb
The next-generation wireless broadband technology is changing the way we work, live, learn, and communicate through effective use of state- of-the-art mobile broadband technology. The packet-data-based revolu- tion started around 2000 with the introduction of 1x Evolved Data Only (1xEV-DO) and 1x Evolved Data Voice (1xEV-DV) in 3GPP2 and High Speed Downlink Packet Access (HSDPA) in 3GPP. The wireless broad- band fourth-generation technology (4G) is an evolution of the packet- based 3G system and provides a comprehensive evolution of the Universal Mobile Telecommunications System specifications so as to remain competitive with other broadband systems such as 802.16e (WiMAX)
标签： Essentials LTE-A LTE and of
上传时间： 2020-05-27
上传用户：shancjb
With the rapid growth in the number of wireless applications, services and devices, using a single wireless technology such as a second generation (2G) and third gener- ation (3G) wireless system would not be efficient to deliver high speed data rate and quality-of-service (QoS) support to mobile users in a seamless way. The next genera- tion wireless systems (also sometimes referred to as Fourth generation (4G) systems) are being devised with the vision of heterogeneity in which a mobile user/device will be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN) simultaneously.
标签： Heterogeneous Wireless Networks Access
上传时间： 2020-05-27
上传用户：shancjb
The first Third Generation Partnership Project (3GPP) Wideband Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA networks are deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is expected to be available in the near future. 3GPP has defined the WCDMA operation also for several additional bands, which are expected to be taken into use during the coming years.
标签： HSDPAHSUPA Access Speed Radio UMTS High for
上传时间： 2020-05-27
上传用户：shancjb
For nearly a hundred years telecommunications provided mainly voice services and very low speed data (telegraph and telex). With the advent of the Internet, several data services became mainstream in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks. Today, high-speed data services are already part of our daily lives at work and at home (web surfing, e-mail, virtual private networks, VoIP, virtual meetings, chats...). The demand for high-speed data services will grow even more with the increasing number of people telecommuting.
上传时间： 2020-05-27
上传用户：shancjb
Wireless metropolitan area networks (WirelessMANs) is emerging as a promising broadband wireless access (BWA) technology to provide high-speed, high bandwidth efficiency and high-capacity multimedia services for residential as well as enterprise applications. It is observed that WirelessMAN (e.g., WiMAX) is even regarded as a 4G technology. For the success of the WirelessMANs, international standardization organiza- tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea WiBro.
标签： BroadbanMobile WiMAX Toward Broadband Wirelessd Wireless Mobile Toward WiMAX
上传时间： 2020-05-30
上传用户：shancjb
With the rapid growth of the wireless mobile applications, wireless voice has begun to challenge wireline voice, whereas the desire to access e-mail, surf the Web or download music (e.g., MP3) wirelessly is increasing for wireless data. While second generation (2G) cellular wireless systems, such as cdmaOne1, GSM2 and TDMA3, introduced digital technology to wireless cellular systems to deal with the increasing demand for wireless applications, there is still the need for more spectrally efficient technologies for two reasons. First, wireless voice capacity is expected to continue to grow. Second, the introduction of high-speed wireless data will require more bandwidth.
标签： Wireless Systems Mobile Beyond and 3G
上传时间： 2020-05-30
上传用户：shancjb
Emerging technologies such as WiFi and WiMAX are profoundly changing the landscape of wireless broadband. As we evolve into future generation wireless networks, a primary challenge is the support of high data rate, integrated multi- media type traffic over a unified platform. Due to its inherent advantages in high-speed communication, orthogonal frequency division multiplexing (OFDM) has become the modem of choice for a number of high profile wireless systems (e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
标签： OFDM-Based Broadband Networks Wireless
上传时间： 2020-05-31
上传用户：shancjb
