Course #15

Design and Simulation of RF Systems - Applications and Technologies

October 4-8, 2010. Copenhagen, Denmark

INSTRUCTOR
Dr. Rowan Gilmore, Australian Institute for Commercialisation and University of Queensland, Brisbane, Australia

TECHNOLOGY FOCUS 
The increasing level of complexity and circuit integration in modern wireless systems requires not only understanding of the design of circuits, but of subsystems as well. RF circuits are typically designed to meet power, efficiency, gain, linearity and noise specifications when driven by single or two-tone excitations; whereas the RF radio system is driven by much more complex signals and must be designed to meet specifications like bit error rate, dynamic range, and minimum detectable signal in the presence of interferers. Only through understanding the interactions between circuits, and through careful simulation, can all the specifications be reconciled. 

COURSE CONTENT 
This popular 5-day course has just been updated with the latest example of a commercial microwave digital radio link, and will show how some of the most recent wireless systems technology is put into practice.
We will focus on examining tradeoffs in the design of  wireless systems, and show how to seamlessly move between both the circuit and system level in radio transceivers and other RF systems. We do this by looking at typical radio architectures, exploring the design tradeoffs, and simulating at both the circuit and system level. The course treats digitally coded signals in RF and IF components, and explores the compromises that are inherent in the design of a radio transceiver. From the RF perspective, the need to minimize interference from nearby unwanted stronger signals and to allow detection of a desired signal in noise is critical. Avoiding corruption of other signals sharing the spectrum is equally critical. Achieving both together is not so simple! 

In wireless LAN for instance, we will see how tradeoffs made to improve performance in some parts of the system, such as multipath reception, have placed tight constraints on other parts of the system, such as the linearity and efficiency of the transmitter. We will interactively simulate a double super-heterodyne, dual-band radio receiver, a direct conversion receiver, and an I-Q modulator and transmitter, as well as various components that make up these systems. This provides the opportunity to explore 'what if?' scenarios. We will also get "inside" the circuits themselves for a greater understanding of how each component works, and contributes to overall system performance.

To benefit most, bring your own laptop computer and, prior to attending, obtain a free trial license of the Visual Systems Simulator (VSS) from AWR at www.awrcorp.com. 
On completion of the course, you will be: 

• Familiar with the air-interface specifications of a mobile radio system, and understand how the key parameters relate to RF hardware 
• Able to simulate various types of RF and IF systems and component interactions
• Able to specify the key components within a system to meet its RF requirement
• Comfortable with reading integrated circuit data sheets for wireless systems, their architecture, and specifications 
• Able to understand the compromises in choosing architectures and circuits to meet given system requirements. 

Monday 

Radio Systems and Digital Communications 
We start by reviewing digital wireless communications and a variety of modulation formats, and the tradeoffs between capacity, bandwidth, signal power, and noise. We look at the upconversion and downconversion processes in typical receiver and transmitter architectures, and the effects of filtering. 

• Revision of Communication and Information Theory Principles 
• Coding and Modulation Formats
• Baseband Filtering and Digital Sampling
• Typical Receiver System Architectures - Direct Conversion, Superheterodyne, Dual Conversion Superheterodyne 

Tuesday 
We will look at a simplified form of the air-interface specification for a basic (CDMA) radio system. This describes the overall radio system requirements and enables multiple system operators to co-exist and interoperate. We will examine the key system parameters that have to be measured - parameters such as noise, distortion, sensitivity, selectivity, and interference. We also examine how the IF is chosen. 

Characterization of Receivers 

• Noise in Receivers
• Selectivity, Sensitivity and Minimum Detectable Signal 
• Nonlinearities and Third-Order Intermodulation Distortion
• Reception in the Presence of Interferers
• Dynamic Range and How to Improve It with AGC 

Characterization of Transmitters 

• Power and Harmonic Distortion 
• Spurious Products
• ACPR, Spectral Regrowth and Linearity with Different Modulation Formats
• Efficiency 

Frequency Selection 

• The Image Frequency
• Choosing the Correct Intermediate Frequency 

Wednesday 
Next, we will see how these system parameters can be met by assembling a number of components. We will turn to their data sheets to discover how each is characterized, and examine the tradeoffs involved in selecting them. We will extract key defining features that describe the behaviour of each circuit, and then simulate both the component and the system in the systems simulator. 

Systems Simulation - Behavioral Modeling 

Simulation of a Dual-band CDMA Superhet Radio Receiver 

• Spreadsheet-based Linear Systems Analysis
• Calculation of Sensitivity and Dynamic Range
• Systems Simulation
• Using AGC to Increase the Dynamic Range
• Effect of Changing the Gain, Intercept Point, and Filtering 

Mixers 

• Spurious Analysis
• Image Reject Mixers
• I-Q Modulators and the Importance of Quadrature 
• Basics of Mixer Design 

Thursday 
We will explore how the key RF functions of amplification, frequency synthesis (oscillation), and frequency translation (mixing) are achieved at the circuit level. This process will highlight some of the key tradeoffs in design, for example, between the power, efficiency, and linearity in a transmitter, and enable us to model these tradeoffs. We will focus on discrete design and review some IC designs. 

Oscillators 

• Basic Concepts of Oscillator Design
• Deriving the Oscillator Tuning Curve and explaining Mode Hopping
• Phase Noise in Oscillators 
• Calculating Allowable Phase Noise from System Specifications 

Power Amplifiers 

• Design Tradeoffs between Linearity, Power, and Efficiency 
• Classes of Amplifier Operation 
• Simulation of Spectral Regrowth with Different Modulation Formats

Examples of Commercial Integrated Sub-Systems-on-Chip

Simulation of a Radio Transmitter 

Friday 
Finally, we look at a variety of challenges facing the systems designer; we examine some 'real' air interface specifications, and we work an example of the complete design process, from air interface specification through to circuit design. 

Topics in Software Defined Radio

• ADC, DSP, Transceiver Issues 

Simulation of a Direct Conversion Receiver 

Trade-off between Modulation Scheme, Data Rate, RF Bandwidth, 
Channel Filter, Power, Noise, Phase Noise, and Bit-Error Rate 
Interpreting Air Interface Specifications 

• CDMA (Narrowband and Wideband)
• Sample 3G WCDMA Requirements 

Design Considerations of Typical Wireless GaAs and CMOS Chip Sets

Regular Course Fee, 5 days: EUR 2995

Early Registration Course Fee, 5 days: EUR 2725
This applies to firm registrations received 2 months before course start. 

University Student and Faculty Rate:
Two university participants are welcome to attend for one course fee if payment is to be made from university funds.

Deliverables:
The course fee covers tuition, course material, and the day conference packages (morning/afternoon refreshments, lunches etc.), paid on your behalf to the course venue. Accommodation is not included.

Payment should be made before course start.