Link budget

About: Link budget is a research topic. Over the lifetime, 1355 publications have been published within this topic receiving 19738 citations.

An Introduction to Free-space Optical Communications

Abstract: Over the last two decades free-space optical communication (FSO) has become more and more interest- ing as an adjunct or alternative to radio frequency commu- nication. This article gives an overview of the challenges a system designer has to consider while implementing an FSO system. Typical gains and losses along the path from the transmitter through the medium to the receiver are in- troduced in this article. Detailed discussions of these topics can be found in this special issue of the Radioengineering Journal.

An Introduction To Ultra Wideband Communication Systems

Abstract: Preface. Acknowledgments. 1. Introduction. Fundamentals. Overview of UWB. A Brief History of UWB Signals. Types of UWB Signals. Regulatory, Legal, and Other Controversial Issues. What Makes UWB Unique? Time Domain Design. Impact of the Antenna. Propagation and Channel Models. Transmitter and Receiver Design. Difficulties in Using DSP Technology. Networking Issues. Future Directions. The I-UWB System Model. Overview of the I-UWB System. Pulse Shapes. Modulation Schemes. MultipleAccess Schemes. Receiver Decision Statistic. The MC-UWB System Model. Overview of the MC-UWB System. OFDM UWB. Overview of the Book. 2. Channel Measurement and Simulation. Introduction. Measurement Techniques. Time Domain Measurement Techniques. Frequency Domain Measurement Techniques. Measurement Results. Typical Results for Time Domain Measurements. Typical Results for Frequency Domain Measurements. The Role of Antennas. Impact of Building Architecture and Properties of Building Materials. Electromagnetic Simulation of UWB Propagation in Indoor Environments. Simulation of Transmitting and Receiving Antennas. Simulation of the UWB Channel. Organization of the Electromagnetic Simulator. Comparisons of Measurement and Simulation Results. Summary. 3. Channel Modeling. Introduction. What's Different about UWB? Large-Scale Channel Modeling. Free-Space Path Loss Modeling: The Friis Transmission Formula. Path Loss Modeling for Non-Free-Space Environments. Frequency Dependent Models. Partition Dependent Approaches. Large-Scale Modeling Studies. Antenna Impact on Large-Scale Modeling. Better than Free-Space Propagation. Receiver-Dependent Path Loss Models. Shadowing. Link Budget Calculations. Small-Scale Channel Modeling. Statistical Modeling of the Channel Impulse Response. Saleh-Valenzuela Model. -K Model. Single Poisson Model. Modified Poisson Model. Split-Poisson Model. Effect of Model Parameters. Stochastic Tapped-Delay Line Model. Amplitude Statistics. Summary of Measurement Campaigns and Modeling Efforts. Spatial Behavior and Modeling of UWB Signals. Introduction. Spatial Fading. Spatial Fading of Signal Components. Spatial Correlation. A Two-Dimensional Channel Model for UWB Indoor Propagation. Impact of Frequency Distortion on Discrete Channel Modeling. The CLEAN Algorithm. Impact of Frequency Dependent Distortion. Impact of Reflections. Summary. 4. Antennas. Basic Properties of Antennas. Reciprocity and Antenna Effective Length. Directivity, Gain, and Related Definitions. A Link Model Using S-Parameters. Link Budget Concepts. Fundamental Limits of Antennas. Antenna Measurements and Modeling in the Time Domain. Basic Responses. UWB Performance. Frequency and Time Relationships. Pattern Concept in Time. Time Domain Modeling (A Minimal Approach). Transient Responses of Scatterers. Summary. 5. Transmitter Design. I-UWB Signal Generators. Avalanche Pulse Generators. Step Recovery Diode Pulse Generators. Tunnel Diode Pulsers. Pulse Circuits Suitable for Integrated Circuits. Modulators. I-UWB Transmitters. TH-PPM and TH-(A-PAM) UWB Signals. OOC-PPM UWB Signals. DS-UWB Signals. Transmitter Reference (TR) UWB System. MC-UWB Transmitters. CI-UWB Signals. FH-UWB System. OFDM-UWB System. Spectral Encoded UWB Communication System. Summary. 6. Receiver Design Principles. I-UWB - RadioReceivers. System Model. Threshold/Leading Edge Detection. Correlation Detection (CD) Receivers. RAKEReceivers. Multi-User Detection (MUD) UWB Receivers. Hybrid RAKE/MUD UWB Receivers. Other I-UWB Receivers. Autocorrelation Transmitted Reference (TR) UWB Receiver. Synchronization and Timing Issues. Digital I-UWB Implementation. Example of IEEE Proposed Standards for PPM and DS-Based UWBReceivers. MC-UWBReceivers. Carrier Interferometry (CI) UWB Receiver. Frequency Hopped (FH) UWB Receivers. OFDM-UWBReceivers. Example on IEEE Proposed Standard for MC and OFDM-Based UWB Receivers. Spectral Encoded UWB Communication System. CaseStudy: Improving Range of UWB Using RAKE Receivers. GSC(N, L)withIndependent but Nonidentically DistributedFading Statistics. PMRC(N, L)withIndependent but Nonidentically DistributedFading Statistics. GSC(N, L)withEqually Correlated Nakagami-m FadingStatistics. Summary. 7. On the Coexistence Of Uwb and Narrowband Radio Systems. Introduction. Interference of UWB on NB: Waveform Analysis. UWB Pulse Model. Effect of NB Receive Filter. BER Analysis. Time-Hopped Case. Simulation Results. Aggregate UWB Interference Modeling. Received Power. Asymptotic Pdf of Aggregate Noise. Amplitudes: Aggregate Pdf. Bernoulli and Poisson Models. Simulation Examples. Interference Analysis: NB on UWB. Interference Analysis: UWB on UWB. Summary. 8. Simulation. What's Different about UWB SystemSimulations? Direct/Quadrature Signal Decomposition. Model Development for UWB Systems. UWB Simulation Development Challenges. Developing a Simulation. Simulation Methodologies-A Brief Review. Monte Carlo Simulation Techniques. Semi-Analytic Simulation Techniques. Discrete Event Simulation Techniques. Multicarrier UWB (MC-UWB) Simulation. UWB Component Simulation. UWB Pulse Generation and Modulation. Signal Ampli?cation. Simulation of Antenna Effects. Simulation of UWB Channels. Summary. 9. Networking. How Is UWB Networking Different? UWB Physical Layer Issues. Data Link Layer Design. Objectives of the Data Link Layer. Contention-Based Medium Access Control. ChannelPartition Medium Access Control. MultipleAccess Protocols for UWB Networks. Forward Error Correction and Automatic Repeat Request. UWB Multiple Hop Ad Hoc Networks. Hierarchical Network Topologies. Flat Network Topologies. Other Networking Issues. TCP Performance in a Wireless Environment. Quality of Service Management. Summary. 10. APPLICATIONS AND CASE STUDIES. Specialized Applications for UWB Signals. Applications. High Resolution Radar Applications. Communications Applications. Location Aware Communications Applications. Channel Sounding Applications. Case Studies. XtremeSpectrum Incorporated (XSI)/Motorola Trinity Chipset. Time Domain Corp-PulsON Chipset. Multispectral Solutions Incorporated (MSSI). Aether Wire and Location Localizers. 802.15.3a. 802.15.4a Devices. Summary. Appendix A. Range Analysis of UWB Signals Using Time of Arrival. Appendix B. UWB Standards for WPANs. IEEE 802.15.3/3a MAC. IEEE 802.15.3a PHY. MB-OFDM PHY. DS-UWB PHY. Summary. Appendix C. UWB Regulations. FCC. World. About The Editor. About The Authors. Index.

Initial Access in 5G mmWave Cellular Networks

Abstract: The massive amounts of bandwidth available at millimeter-wave frequencies (above 10 GHz) have the potential to greatly increase the capacity of fifth generation cellular wireless systems. However, to overcome the high isotropic propagation loss experienced at these frequencies, highly directional antennas will be required at both the base station and the mobile terminal to achieve sufficient link budget in wide area networks. This reliance on directionality has important implications for control layer procedures. In particular, initial access can be significantly delayed due to the need for the base station and the user to find the proper alignment for directional transmission and reception. This article provides a survey of several recently proposed techniques for this purpose. A coverage and delay analysis is performed to compare various techniques including exhaustive and iterative search, and context-information-based algorithms. We show that the best strategy depends on the target SNR regime, and provide guidelines to characterize the optimal choice as a function of the system parameters.

Steering with eyes closed: Mm-Wave beam steering without in-band measurement

Abstract: Millimeter-wave communication achieves multi-Gbps data rates via highly directional beamforming to overcome pathloss and provide the desired SNR. Unfortunately, establishing communication with sufficiently narrow beamwidth to obtain the necessary link budget is a high overhead procedure in which the search space scales with device mobility and the product of the sender-receiver beam resolution. In this paper, we design, implement, and experimentally evaluate Blind Beam Steering (BBS) a novel architecture and algorithm that removes in-band overhead for directional mm-Wave link establishment. Our system architecture couples mm-Wave and legacy 2.4/5 GHz bands using out-of-band direction inference to establish (overhead-free) multi-Gbps mm-Wave communication. Further, BBS evaluates direction estimates retrieved from passively overheard 2.4/5 GHz frames to assure highest mm-Wave link quality on unobstructed direct paths. By removing in-band overhead, we leverage mm-Wave's very high throughput capabilities, beam-width scalability and provide robustness to mobility. We demonstrate that BBS achieves 97.8% accuracy estimating direction between pairing nodes using at least 5 detection band antennas. Further, BBS successfully detects unobstructed direct path conditions with an accuracy of 96.5% and reduces the IEEE 802.11ad beamforming training overhead by 81%.

A 28GHz Bulk-CMOS dual-polarization phased-array transceiver with 24 channels for 5G user and basestation equipment

Abstract: Developing next-generation cellular technology (5G) in the mm-wave bands will require low-cost phased-array transceivers [1]. Even with the benefit of beamforming, due to space constraints in the mobile form-factor, increasing TX output power while maintaining acceptable PA PAE, LNA NF, and overall transceiver power consumption is important to maximizing link budget allowable path loss and minimizing handset case temperature. Further, the phased-array transceiver will need to be able to support dual-polarization communication. An IF interface to the analog baseband is desired for low power consumption in the handset or user equipment (UE) active antenna and to enable use of arrays of transceivers for customer premises equipment (CPE) or basestation (BS) antenna arrays with a low-loss IF power-combining/splitting network implemented on an antenna backplane carrying multiple tiled antenna modules.