Microwave & Fixed LOS Link Design in Depth
- Introduction
- Microwave and other radio systems: Microwave versus copper cable, fiber optics, and leased services
- Microwave frequency bands
- Regulatory matters: Rules, regulations and recommendations; radio licenses and permits. Regulatory agencies (FCC or your national body)
- Characteristics of Voice, Data, and Video
- Combining various signals
- Channelizing the radio spectrum: Frequency, time, and code division multiple access (FDMA, TDMA, CDMA)
- History of Analog Microwave Radio
- Frequency Division Multiplex (FDM) techniques and hierarchies
- L Carrier and ITU frequency plans
- Digital Transmission Systems
- Sampling theory
- Time Division Multiplex (TDM) techniques and hierarchies
- North American and ITU digital hierarchies
- Plesiochronous Digital Hierarchy (PDH)
- Synchronous networks (SDH/SONET)
- Digital Power Spectra and Bandwidths
- Bandwidth definitions and requirements
- Nyquist and other shaping
- Regulatory masks
- Baseband data signals
- Filtering and rolloff factors
- Digital Modulation
- Amplitude, frequency, and phase shift keying (ASK, FSK, PSK)
- Binary versus M-ary modulation
- QPSK, Offset QPSK, and
/4 QPSK
- Minimum Shift Keying (MSK)
- QAM and Trellis Coded Modulation (TCM)
- Orthogonal FDM (OFDM)
- Line of Sight Transmission
- Free space loss
- Effect of terrain
- Reflection and diffraction
- Fresnel zones and path profiles
- Clearance requirements
- Effects of Climate
- Refraction and variations in radio refractivity (N factor)
- Snell’s law and the effective earth radius (K factor)
- Rain attenuation; specific rain rate and effective path length; ITU rain attenuation model
- Other atmospheric attenuation
- Prediction of outage using computer models
- Fading
- Multipath fading
- Reflection and diffraction causes
- Rayleigh, Rician, and log-normal statistics of fading
- Multipath propagation models; Barnett-Vigants observations; ITU models
- Diurnal and seasonal variations
- Effect of Fading on Digital Radio
- Flat versus frequency selective fading
- Minimum versus non-minimum phase fading
- M and W curves
- Flat, dispersive, and composite fade margins
- Calculation of estimated outage using computer models
- Equalization
- Linear versus non-linear equalization
- Transversal filter
- Zero-forcing equalization versus minimum mean-square error
- Decision feedback equalization and training equalizer
- Antennas and Diversity
- Antennas types and parameters: Gain, directivity, radiation pattern, polarization, beamwidth
- Waveguide types and characteristics: Rectangular, circular
- Diversity types: Space, frequency, angle, polarization, hybrid
- Diversity combining and improvements over non-diversity systems
- Forward Error Correction
- Definition of coding types and coding gain
- Types of block codes with examples: CRC and Hamming codes
- Convolutional coding and Viterbi decoding, with example
- Interleaving and turbo codes
- Radio Frequency Interference (RFI) Coordination
- Interference analysis for co-channel and adjacent-channel
- Carrier-to-Interference (C/I) ratio
- Threshold-to-interference (T/I) ratio
- Manual and computer-aided design for intra- and inter-system interference
- Frequency planning
- Satellite and other external interference
- Detailed analysis of a terrestrial RFI case
- Performance Objectives
- Single link, tandem link, and end-to-end objectives
- U.S. and ITU standards and recommendations
- Availability and error rate objectives
- Measurements of bit error rate, eye patterns, and jitter
- Acceptance Testing and Performance Monitoring
- Factory tests; BER testing
- Use of spectrum and link analyzers
- Propagation instrumentation
- On-line performance measurement
- Fade margin testing
- Fault isolation and performance monitoring
- Path Engineering
- Manual and computer-aided design
- Site selection, mapping, path profile generation and analysis
- Reflection point analysis
- Selection of components to meet performance objectives
- Software examples; hands-on exercise designing paths; analysis of problem path
- Use of digitized terrain data from USGS Digital Elevation Models for path profiles
- Wrap-up: Course Recap, Q/A, and Evaluations
