Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Analysis of Vector Quantizers Using Transformed Codebooks with Application to Feedback-Based Multiple Antenna Systems
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Timing-Free Blind Multiuser Detection for Multicarrier DS/CDMA Systems with Multiple Antennae
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Multihop relaying and multiple antenna techniques: performance trade-offs in cellular systems
ADC’s Digivance® Street-Level Coverage
Solution (SCS) helps wireless service providers
improve capacity in areas where restrictive
zoning requirements prohibit deployment of
traditional base station network equipment.
The SCS distributed antenna system (DAS)
utilizes patented digital RF transport-overfiber
technology to distribute wireless
service between existing cell sites and SCS
remote antenna units. The small-form-factor,
environmentally hardened, Remote Units
offer multiple mounting options that easily
blend into the existing environment.
This book covers the most recent advances concerning the ability to overcome connectivity
limitations and extend the link capacity of vehicular systems. Ranging from the
advances on radio access technologies to intelligent mechanisms deployed to enhance
cooperative communications, cognitive radio and multiple antenna systems have been
given particular highlight.
Wireless communications is one of the most active areas of research over the
past and the current decades. In fact, the demand for wireless services has been
changing from the regular voice telephony services to mixed voice, data, and
multimedia services over the wireless media. Since the mid-1990s, the wireless
industry has been advancing at an incredible speed. For example, the 2G cellular
systems (such as GSM, D-AMPS, and IS-95) have significantly improved
the spectral efficiency and network capacity to support wireless telephony
This report has been reviewed in draft form by persons chosen for their
diverse perspectives and technical expertise in accordance with procedures
approved by the National Research Council’s Report Review Committee.
The purposes of this review are to provide candid and critical comments
that will assist the institution in making the published report as sound
as possible and to ensure that the report meets institutional standards of
objectivity, evidence, and responsiveness to the study charge.
This book provides a comprehensive introduction to the underlying theory, design techniques and analytical tools of wireless communications, focusing primarily on the core principles of wireless system design. The book begins with an overview of wireless systems and standards. The characteristics of the wireless channel are then described, including their fundamental capacity limits. Various modulation, coding, and signal processing schemes are then discussed in detail, including state-of-the-art adaptive modulation, multicarrier, spread spectrum, and multiple antenna techniques....
The Digivance Indoor Coverage Solution (ICS) is used to extend coverage to specific areas
within a building, multiple buildings, or throughout a campus environment. This digital
distributed antenna system (D-DAS) solution features unique, patented technology that
distributes wireless coverage digitally over optical fiber, making Digivance ICS the best
choice for signal quality, flexibility, and overall performance. Its digitized optical RF transport
also future-proofs in-building wireless infrastructure for higher data rate services.
Today’s cable systems serve up more than just television. Because community
antenna television (CATV) systems now incorporate high-speed data and
telephony services, signal flow is critical for multiple systems operators (MSOs)
and their customers. Signal levels and network configurations must evolve
to meet the new service demands of transitioning headends. The impending
challenge for MSOs is to effectively manage their networks amid change and
maintain maximum uptime for subscribers.
Segment Design Tradeoffs
I. OVERVIEW The six steps in the systems-level design process associated with the software radio are illustrated in Figure 6-1. The tradeoffs proceed from front end to back end. The choice of antennas (step 1 in the figure) determines the number and bandwidth of RF channels (step 2). This, in turn, constrains the numbers and bandwidths of ADCs (step 3). Some waveforms may require dedicated ASICs (e.g., W-CDMA despreaders) in front of the ADCs. Additional parallel IF processing and ADC paths may be necessary to support multiple-service bands simultaneously....
Hybrid Multiple Access Schemes
The simultaneous transmission of multiple data streams over the same medium can be achieved with different multiplexing schemes. Most communications systems, such as GSM, DECT, IEEE 802.11a, and HIPERLAN/2, use multiplexing based on either time division, frequency division or a combination of both. Space division multiplexing is applied to further increase the user capacity of the system. The simplest scheme of space division multiplexing is antenna sectorization at the base station where often antennas with 120◦ /90◦ beams are used....