Apparatus and method for encoding constant amplitude in code division multiplexing communication system

A constant amplitude encoding apparatus that is applied to a code division multiplexing communication system, the constant amplitude encoding apparatus comprising:

• an input frame generation module that divides a data bit string into a predetermined length and that generates a cyclic redundancy check bit of the divided data bit string and that adds the cyclic redundancy check bit to the divided data bit string to generate an input frame;
• a 1/N conversion module that forms the input frame into a plurality of blocks according to a predetermined block code rate;
• an interleaving module that converts the plurality of blocks to a matrix by filling in one direction of a horizontal direction and a vertical direction and that reads out the converted matrix in a direction different from the filled direction of a horizontal direction and a vertical direction to output the converted matrix to a series of bit strings;
• a 9/16 turbo product code module that outputs an encoded result by adding an additional bit to the output of the interleaving module;
• and
• a constant amplitude multiplexing module that performs a constant amplitude multiplexing process on the output of the 9/16 turbo product code module.