Angle diversity with rate-adaptive transmission using repetition coding and variable silence periods for wireless infrared communications

The simultaneous use of a simple rate-adaptive transmission scheme based on the use of variable silence periods and a new self-orienting receiver, as an alternative to conventional angle diversity techniques, is proposed in order to mitigate the effect of large variations of the signal-to-noise ratio (SNR) in indoor wireless infrared communications. In relation to the rate-adaptive transmission technique, variable silence periods are used so as to increase the peak-to-average optical power ratio (PAOPR). With regard to the new diversity technique proposed, this is based on giving a self-orienting capability to the optical front-end, optimizing link quality parameters. We apply it to links operating at high initial bit rates of 50, 100 and 200 Mb/s, providing a signaling rate with a wide dynamic range and a. relevant improvement in performance with a gradual complexity in implementation, compared with the scheme, proposed and specified in the advanced infrared (AIr) standard by the Infrared Data Association (IrDA), which is based on repetition coding and pulse-position modulation.