Agilent EEsof EDA Wireless Networking Design Seminar - Archive

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Wireless networking radio system design and verification requires accurate generation and analysis of complex modulated RF signals, such as IEEE 802.11a/b wireless local area networking (WLAN) and Bluetooth. Simulation and testing is ideally performed with real-world signal impairments and component distortion included. In this one-day seminar, Agilent Technologies application engineers discuss four key topics in wireless networking. Click on the following links for more information: • Seminar Overview/Registration • Seminar Papers and ADS Project Files • Agilent Technolgies Products

Wireless Networking Design Seminar: 27 November 2001 -
22 January 2002

In this free one-day seminar, Agilent Technologies application engineers will present both software and hardware solutions for wireless networking.

Software solutions will include ADS simulation of wireless LAN systems and an 802.11a DesignGuide. Combined hardware and software solutions presented will include design verification for IEEE 802.11a 5 GHz wireless LAN systems.

WLAN and Bluetooth demos will highlight the benefits of software/hardware connected solutions. Agilent Technologies application engineers will also be available to discuss your particular design and measurement challenges.

Seminar Papers and ADS Project Files

Paper 1: Wireless Networking Design and Verification

Wireless networking radio system design and verification requires accurate generation and analysis of complex modulated RF signals such as those associated with IEEE802.11a/b wireless local area networking (WLAN) and Bluetooth personal area networking (PAN). This paper shows how virtual measurements are performed in wireless networking simulations and demonstrates transmitter signal emulation using IQ arbitrary waveform generators. Signals originate in both simulation and measurement domains, and are recorded for reuse in system design, integration, and test using a Vector Signal Analyzer (VSA).

WLAN 802.11a receiver verification requires accurate transmit test signals with short and long preambles, signaling, and data contents. This transmit information is used for receiver adjustments and adaptive equalization. Ideally, transmitter signal impairments and distortion are included in verification testing. Moving complex signals, data, and test vectors between simulation and measurement domains speeds up the troubleshooting processes, making it easier to correlate results, validate prototype designs early, and shorten design cycles.

PDF File   (37 slides and notes, 4.7 MB)

WNet80211a_nov19.zap   (ADS Project File, 67 KB)
VSA_dot11b_nov19.zap   (ADS Project File, 2.1 MB)
VSA_Source_ADS2001_nov19.zap   (ADS Project File, 1.0 MB)
VSA_Bluetooth_TIS2_nov19.zap   (ADS Project File, 34 KB)

Paper 2: Measuring and Troubleshooting OFDM Wireless LAN Signal Quality

Multi-carrier modulation schemes such as OFDM represent significant challenges when seeking to verify PHY-layer characteristics. While traditional spectrum analyzers measure simpler parameters such as frequency, power level, and spectral mask, in-depth quality measures such as error vector magnitude, carrier feedthrough, I-Q match, burst parameters, and so on, require special capabilities found only in vector signal analyzers (VSAs).

Agilent's 89600-series broadband VSAs are enhanced to provide a rich set of OFDM-specific analysis tools for the wireless LAN engineer. Along with fully verifying the PHY-layer requirements of IEEE 802.11a, they offer the flexibility and in-depth insights needed to track even subtle signal problems back to their source.

This paper begins by reviewing and contrasting the characteristics of single- and multi-carrier systems, as viewed at the PHY layer. It then presents the new set of analysis and visualization tools created by Agilent for characterizing OFDM signals, along with a detailed discussion on how to interpret their results. It concludes with a series of case studies in which common signal impairments - amplifier saturation, I-Q imbalance, quadrature error, linear distortion, and so on - are identified and localized using these tools.

PDF File   (39 slides and notes, 2.9 MB)

Paper 3: Simulation of Wireless LAN System

This paper introduces the ADS wireless LAN (WLAN) simulation environment for 5-GHz high-data-rate IEEE 802.11a WLAN systems. This environment helps designers select the correct power amplifier in the early stages of the design process.

One of the most serious problems in an OFDM (Orthogonal Frequency Division Multiplexing) is the high peak-to-average power ratio. It is important to improve the accuracy of models used to simulate nonlinear power amplifier behavior under OFDM stimulus to improve the accuracy of output RF spectrum and Adjacent Channel Power Ratio (ACPR) measurements.

To achieve accurate simulations, however, designers need more than accurate behavioral models. This paper demonstrates circuit simulation results and behavioral models within an accurate test and verification setup to measure CCDF (Complementary Cumulative Distribution Function), ORFS (Output RF spectrum) and EVM (Error Vector Magnitude).

PDF File   (28 slides and notes, 1.9 MB)

Paper 4: Simulation of OFDM Impairments Using ADS WLAN 802.11a Library and DesignGuide

This paper demonstrates the WLAN 802.11a DesignGuide, which streamlines the process of evaluating IEEE802.11a measurements under various link impairments. Operating within the powerful ADS 2001 simulation environment, this DesignGuide provides test templates that streamline the evaluation process.

Test templates include:

• Frequency offset between transmitter and receiver.

  OFDM systems are very sensitive to carrier frequency offsets. Even tiny offsets can cause significant degradation in system performance. Therefore, synchronization of the carrier frequency at the receiver must be accurate. This type of test result is demonstrated using the DesignGuide.

• Oscillator phase noise.

  Even if the receiver is perfectly synchronized, frequency conversion for RF and microwave channels unavoidably imposes phase noise, a portion of which is untracked and therefore contributes to system BER degradation. The DesignGuide and an ADS simulation show the phase noise distortions.

• Fixed-point effect in FFT/IFFT.

  Fixed-point degradation due to the IFFT/FFT section of the OFDM is critical, because IFFT/FFT is the most intensively power hungry section of any OFDM signalling. The fixed-point effect and system performance tradeoffs are demonstrated and discussed.