Programmable Wireless Baseband Chip Handles Any OFDM Standard
Virtually all modern wireless standards have adopted orthogonal frequency division multiplexing (OFDM) as their modulation and access method. Wi-Fi 802.11a/g/n uses it. So do the mobile and fixed versions of WiMAX 802.16 and the Korean WiBro standard. The fourth-generation cell-phone standard known as Long Term Evolution (LTE) relies on OFDM. The XG-PHS cell-phone standard in Japan and China take advantage of it as well.
But not all OFDM is alike. Individual methods may be very similar but just different enough to be a nuisance in most cases, making it necessary to create different silicon for each application. On the other hand, designers can implement any one of these standards with Wavesat’s Odyssey 8500 broadband wireless chip.
The fully programmable Odyssey 8500 baseband chip works with a wide range of available RF front ends. Its eight programmable DSPs handle all the OFDM and related processing, including multiple-input/multiple-output (MIMO) and other features. The chip also includes a PowerPC RISC processor and 32 Mbits of DRAM for related control functions (see the figure).
Peripherals include the usual serial peripheral interface (SPI), general-purpose I/O (GPIO), and universal asynchronous receiver transmitter (UART). Also included are a USB controller, secure data I/O (SDIO) controller, host port interface (HPI) controller, and a universal integrated circuit card (UICC) and SIM card controller.
In addition to its programmability and attendant flexibility, the Odyssey’s very small size, very low power consumption, and efficiency make it highly desirable in customer premise equipment (CPE) as well as in handsets and other portable devices. It truly is a single-chip solution for forthcoming 4G systems and equipment. The Odessey 8500 is sampling now. Production quantities are expected to ship by the third quarter of 2008.
Wavesat Inc.
