Multiple subcarrier modulation for infrared wireless systems using punctured convolutional codes and variable amplitude block codes

We propose multiple subcarrier modulation (MSM) for infrared wireless systems using punctured convolutional codes and variable amplitude block codes. The rate-compatible punctured convolutional (RCPC) code deletes the coded bits corresponding to zeros in the puncturing table and does not allocate them on amplitude of the subcarriers. On the other hand, the proposed system maps them to the amplitudes of subcarriers where the amplitudes are selected so that the required bias can be minimized. We propose two systems that use the block codes to map the coded bits corresponding to zeros in the puncturing table: one block code maps them to only zeros (proposed 1), and the other block code maps them to the appropriate values among 0, and /spl plusmn/1, so that the average optical power can be minimized (proposed 2). We show that the proposed 2 tan achieve the minimum required SNR at the same average optical power among all the systems.