Forward error correction gets turbo boost
-- EDN, January 4, 2001
For wireless applications, 3 dB of coding gain translates into your choice of reducing required bandwidth, increasing throughput, or halving transmitter power. Alternatively, you can use the 3 dB to increase range by 40%, reduce antenna size by 30%, or just take the 3dB as a straight reduction in the required noise figure of a receiver. But no matter how you use it, the 3-dB coding gain the Astro LE family from AHA (Advanced Hardware Architecture) gives you via Reed Solomon or Viterbi coding is attractive, especially at the target price of $5 (1 million). The 2-kbit Astro LE operates at channel rates as high as 35 Mbps. The 4-kbit Astro LE offers additional coding gain for less cost-sensitive applications and uses a larger block size of 4 kbits.
Applications for the Astro LE family include modems for high-speed wireless-Internet access, including point-to-multipoint terrestrial and satellite connections, as well as next-generation power-line modems running through standard electrical outlets. The devices use AHA’s TPC (Turbo Product Code) technology, offer coding rates of 0.25 to 0.95% efficiency, operate at half- or full-duplex, and have 5V-tolerant inputs with 3.3V-I/O and 1.8V-core operation. Samples will be available in this quarter, and volume quantities will be available in July.
Advanced Hardware Architecture, www.aha.com.
—by Nicholas Cravotta
