|
The Toshiba Multimedia Engineering Laboratory does research and development for large-scale integrated circuits used in digital satellite receivers, wireless products, and TV tuners. In this case, Toshiba's goal is to design a mixed DSP and RF receiver chipset using a novel architecture to greatly improve performance and reduce size and power for a GSM (DCS 1800) mobile device. This innovative design must meet all GSM standard requirements including adjacent and alternate channel interference. The real challenge is modeling this mixed DSP/RF chipset in which overall performance would be set by system non-idealities.
Optimizing Innovative Mixed DSP/RF Designs with Advanced Design System
In order to meet his design challenge, Toshiba selected Agilent Advanced Design System to implement a top-down design approach. This reduces the design cycle time by enabling optimization and understanding of the system problems before considering implementation detail. This method also enables Toshiba to avoid wasting energy by repeating design cycles. Yasunori Miyahara, Group Leader of Toshiba's Multimedia Engineering Laboratory commented: "We want to use a design process that employs a top-down approach and does not waste time moving back upstream from problems discovered late at the implementation phase. "Miyahara explained he problem is that traditional approaches use separate tools for system, DSP, and RF design without he ability to analyze and understand performance of the entire mixed-signal system.
Unlike traditional tools, the Agilent Advanced Design System contains a powerful mix of system, circuit, and implementation level tools that "lets engineers understand the entire mixed DSP/RF system at any point in the design flow," Miyahara commented. Toshiba chose Agilent's Advanced Design System because it is unique in providing a complete array of capabilities needed to accurately design and implement the half-digital/half-analog chipset.
Optimizing the Chipset Performance
In the chipset, Toshiba uses a digital IF with a very low frequency, which makes it difficult to filter the signal with an analog band pass filter. To address his challenge, a digital image elimination system is employed. |
|
"This method also enables Toshiba to avoid wasting energy by repeating design cycles." |
| |
Yasunari Miyahara
Group Leading, Toshiba Multimedia Engineering Laboratory |
The Agilent Advanced Design System accurately analyzes the effects of digital quantization along with RF non-linearities to determine overall mixed-signal system performance. "Without Advanced Design System, we simply could not do this," stated Miyahara.
Toshiba used the digital filter design tool in the Agilent Advanced Design System. To meet some of the image rejection challenges in the mixed DSP/RF chipset architecture, Miyahara explained that "standard digital filter designs would not allow us to meet the image rejection requirements we needed." Toshiba was able to use the powerful weighting capabilities of the digital filter tool to achieve a notch band in the frequency response and thus meet he desired performance goals. Satisfied with the results achieved, Miyahara observed, "This tool offers many conveniences and has a lot of unique capabilities."
Using the Agilent Advanced Design System, Toshiba was able to design, analyze, and accurately predict the performance of the mixed DSP/RF GSM chipset using a top-down design methodology that reduced design cycles and development time. Ultimately, system design and modeling are only as good as the results achieved in hardware.
After optimizing the system design in the Agilent Advanced Design System, Miyahara confirmed hat "actual measurements show a good match with our predicted system performance."
Using the Agilent Advanced Design System allowed Toshiba to eliminate weeks in the development of his complex mixed-signal GSM chipset. Based on his success, Toshiba expects to continue and expand use of the Agilent Advanced Design System for many future challenging wireless and multimedia projects.
For more information about Agilent EEsof EDA visit: www.agilent.com/eesof-eda
For more assistance with your test & measurement needs visit: www.agilent.com/find/assist
|
Contact Us
