Vector Signal Analyzer offers 802.11g component analysis tools.
Share:
Press Release Summary:
Series 89600 vector signal analyzers (VSAs), with 802.11g WLAN Signal Studio software, includes automatic detection, demodulation, and despreading of 4 mandatory 802.11b signal formats. Software also detects and decodes optional 802.11b, 802.11g PBCC (packet binary convolutional code), and CCK-OFDM (complementary code-keying-orthogonal frequency division multiplexing) formats. With 802.11a analysis, users can skip over 802.11g CCK-OFDM payload and demodulate 802.11a-compatible data payload.
Original Press Release:
Agilent Technologies Offers the Industry's Most Comprehensive 802.11g Analysis and Test Signal Capabilities
Tools for 89600 Vector Signal Analyzer Evaluate PHY Layer Modulation Performance of Equipment Used in All Current and Proposed WLAN Standards
PALO ALTO, Calif., Nov. 12, 2002 -- Agilent Technologies Inc. (NYSE: A) today introduced the industry's most comprehensive array of software-based modulation analysis and troubleshooting tools for designers of 802.11g wireless LAN (WLAN)-compatible transceivers and components.
These enhancements to the Agilent 89600 series vector signal analyzers (VSAs) are among the first analysis tools available to designers of 802.11g components. When combined with Agilent's existing 89600-based 802.11a and 802.11b analysis tools, the new software completes one of the most comprehensive suites available for analyzing the complex signals of all current and proposed WLAN standards -- 802.11a, 802.11b, and 802.11g.
Agilent today also released enhanced capabilities for its 89600 VSA 802.11a and 802.11b WLAN software solutions, including a separate "one-button" 802.11 test application.
Agilent is also introducing the 802.11g WLAN Signal Studio software for the E4438C ESG vector signal generator. This product complements the company's existing 802.11a and 802.11b WLAN Signal Studio waveform generation software, which can be downloaded directly from the Agilent Web site for evaluation. License keys purchased from Agilent are required in the ESG signal generator to download the 802.11 WLAN test signals from the Signal Studio software to the ESG.
Complete Analysis Flexibility
The new 802.11g software for the 89600 series VSA has all of the features of the current 802.11a and 802.11b software. These include the ability to demodulate WLAN bursts to the bit level; a compound constellation display to automatically determine and display all modulation formats present in the signal; and the ability to evaluate modulation quality using error vector magnitude (EVM) displays of the overall burst, each symbol, or each subcarrier in a symbol.
New 802.11g-specific features include automatic detection, demodulation, and despreading of the four mandatory 802.11b signal formats (1, 2, 5.5, and 11 MHz) as well as detection and decoding of the optional 802.11b and 802.11g PBCC (packet binary convolutional code) formats. The software will also detect the optional CCK-OFDM (complementary code-keying-orthogonal frequency division multiplexing) format and automatically detect, demodulate, despread, and descramble the standard 802.11b preamble and short 802.11b preamble (optional in the standard) to determine the expected burst length and modulation type.
Enhancements to 802.11a analysis include the ability to skip over the 802.11g CCK-OFDM payload and demodulate the 802.11a-compatible data payload. The new "one-button" 802.11a test application allows quick and easy standards-based testing on 802.11a signals.
New 802.11g Capabilities for Signal Studio
The 802.11g WLAN Signal Studio software for the E4438C ESG vector signal generator provides a quick and easy way to create test signals for 802.11g component or receiver tests. For component testing, the software enables users to determine the performance characteristics of 802.11g WLAN components and to modify signal parameters to meet customized test needs. In addition, the software can generate statistically correct signals to properly stress components. For receiver testing, the software creates fully coded 802.11g WLAN frames, which enables FER, PER, and BER receiver sensitivity testing and allows demodulation capability of 802.11g WLAN receivers to be verified.
Additional information about these products is available at the following Web sites:
o www.agilent.com/find/89600, for the 89600 vector signal analyzer and 802.11g analysis software;
o www.agilent.com/find/ESG, for the ESG series digital RF signal generator; and
o www.agilent.com/find/signalstudio, for the 802.11 WLAN Signal Studio software for E4438C ESG.
Photos are available at http://www.get.agilent.com/press/index.cgi?PSP_NEXT=ShowPR&Release:release_id=65.
U.S. Pricing and Availability
The Agilent 89600 vector signal analyzers are available now and range in price from $35,000 to $70,000. The 802.11g analysis tools, which will be included in the WLAN Option B7R for the 89600 VSA, are expected to be available in December 2002 at prices below $6,000. The E4438C vector signal generator is available now starting at $17,353. The 802.11g WLAN Signal Studio software is available now at a price of $5,500 or less, depending on previously purchased WLAN Signal Studio license keys.
About Agilent Technologies
Agilent Technologies Inc. (NYSE: A) is a global technology leader in communications, electronics and life sciences. The company's 37,000 employees serve customers in more than 120 countries. Agilent had net revenue of $8.4 billion in fiscal year 2001. Information about Agilent is available on the Web at www.agilent.com.
Sales information is available by calling +1 800 452 4844, ext. 7769.
Information in this news release applies specifically to products available in the United States. Product availability and specifications may vary in other markets.
Readers will receive the quickest response to their inquiries by mailing them to Agilent Technologies, Test and Measurement Organization, 5301 Stevens Creek Blvd., MS 54LAK, Santa Clara, Calif. 95052.
BACKGROUNDER
The Power of Vector Signal Analysis in the Evolving WLAN Environment
There are similarities between the evolution of 2.5G wireless communications systems and WLAN standards. Both sets of standards are characterized by a bewildering array of designations, each with its own specific requirements. WLAN development is even more confusing because the progression of standards into the marketplace hasn't followed the logical, alphabetical order of 802.11a, b, and c, but rather 802.11b, a, and (soon) g. The following will provide a brief background of the current and proposed WLAN standards, and will then discuss the value of vector signal analysis in this design environment.
WLAN Standards
Communications standards in the rapidly evolving WLAN environment can confuse novices and veterans alike. All WLAN standards begin with the IEEE designation "802." In 1997 the IEEE finalized the first standard, 802.11, which operates at 2.4 GHz at a maximum data rate of 2 Mb/s with either frequency-hopping spread spectrum (FHSS) or direct-sequence spread spectrum (DSSS) modulation schemes. Subsequent 802.11 standards (a, b, c, etc.) were identified by the task groups responsible for developing them.
The 802.11a standard operates at 5 - 6 GHz using orthogonal frequency division multiplexing (OFDM) at a data rate up to 54 Mb/s. The 5 - 6 GHz frequency band is much less crowded than the 2.4 GHz band, making 802.11a communications less susceptible to interference. The 802.11b standard increases the initial 802.11 data rate up to 11 Mb/s, and uses the complementary code keying (CCK) modulation technique to improve spectral efficiency and data transmission rate. This standard is by far the most widely used because of the lower cost of 802.11b components. The 802.11g standard combines the lower operating frequency (and lower cost) of 2.4 GHz 802.11b with the OFDM to deliver a maximum 54 Mb/s data rate.
Systems operating under the 802.11g standard will be compatible with 802.11b systems and expandable (with new modems and access points) to the higher data rates of 802.11a, but at 2.4 GHz. The 802.11g standard is expected to be ratified in the second quarter of 2003. Once this occurs, it is likely that multi-standard WLAN products will become widely available. Although there are many other 802.11 letters in the WLAN "alphabet soup," the three just described will have the greatest short-term impact.
Unique Capabilities of Vector Signal Analysis
Designers face measurement challenges specific to each WLAN standard, including sorting out which measurements must be made and with which instruments. In some cases, spectrum analyzers, even those with demodulation capability, cannot fully identify and characterize errors inherent in complex digital signals within the various standards. These instruments can identify a problem, but often not its source. By contrast, the error analysis tools that are the basis of vector signal analyzers, such as Agilent's 89600, can be more accurate and effective. For example, the 89600 can detect and analyze with much greater ease and detail high adjacent-channel power or poorly locked constellations created by RF and DSP-based problems. Incorrect filtering, spurious interference, incorrect interpolation, digital-to-analog-converter (DAC) overflow and symbol timing can increase adjacent-channel power and distort the constellation. The vector signal analyzer is the only instrument that can identify the root cause of the overall problem.
Figure 1 illustrates this concept using a wireless communication signal. The two signals in the figure appear almost identical when viewed with a spectrum analyzer, but the radio that generated them will not be capable of transmitting even a single bit because the second signal is off in its center frequency, symbol clock rate and filter alpha. A spectrum analyzer with demodulation capability shows both signals with high ACPR and a cloudy constellation. However, a vector signal analyzer can identify each problem with a single screen using its display of error vector magnitude (EVM)-versus-time.
Figure 1.
The 89600 performs signal analysis in the time, frequency and modulation domains, and therefore can analyze changing phase, magnitude and frequency. Its PC-based tools help designers dig deep into the constituent parts of the signal to determine the root cause of a problem. Designers of components and systems that build up and send digitally modulated signals can use the versatile instrument to evaluate RF and modulation quality with either standards-compliant or user-created signal parameters at a level of detail unavailable with other methods.
Designers can use Agilent 89600A analysis software with other Agilent instruments, including the E4438C ESG vector signal generators, PSA Series spectrum analyzers, Infiniium oscilloscopes and Advanced Design System (ADS) electronic design automation software. For example, the combination of the 89600, ESG and ADS enables engineers to evaluate simulations or prototype designs even before all of the hardware has been completed. Simulated output from ADS can be downloaded to the ESG, with the resulting waveforms used as a stimulus for prototype hardware. Performance of the hardware can then be measured and analyzed with the 89600.
In short, the 89600 vector signal analyzer, E4438C ESG vector signal generator and ADS software provide a complete design platform. Engineers can use the platform to create products for emerging services based on WLAN standards, such as 802.11g, at any stage in the development process. PSA spectrum analyzers and Infiniium oscilloscopes add still more capabilities. The result is a design environment that requires less cycle time to produce a product with the desired attributes and performance.
