Fujitsu Develops Transmission Amp for Mobile WiMax Handsets
Tokyo, Apr 18, 2007 (JCN) - Fujitsu announced on April 13 that it has developed a high efficient transmission amp for mobile WiMax handsets which maximized talking time by 50 percent and upload traffic speed by 50 percent with double the amp efficiency.
A problem with WiMax's Orthogonal Frequency Division Multiplex (OFDM) was maintaining high power output of transmission amps. Transmission amps mount linearized circuits for fixing strains and consumed much electricity.
To solve this problem, Fujitsu used a linearized circuit that was primarily used in base stations and OFDM processed. By fixing transistor size and matching circuit, the new transmission amp achieves 64QAM - an efficiency of 1.5 fold over conventional 16QAM with transmission speed up from 9Mbps to 13.5 Mbps.