Rate-adaptive modulation techniques for indoor wireless infrared links at bit rates of wide dynamic range

A new and simple rate-adaptive transmission scheme for indoor unguided optical links is proposed. This scheme is based on the use of variable silence periods, allowing the increase of the peak-average optical power ratio, which is a favorable characteristic in wireless infrared communications using intensity modulation with direct detection. Here, it is applied to links operating at high bit rate initially, providing a signaling rate with a wide dynamic range and requiring a very low-complexity implementation. The authors compare this scheme in terms of performance and complexity with the scheme proposed by the IrDA, which is based on repetition coding and pulse-position modulation.