Patent ID: 8520496

Claim:
An apparatus comprising: an encoder outputting a plurality of data streams; wherein the encoder is a turbo encoder employing Quadratic permutation polynomial interleaver; interleaving circuitry individually interleaving each data stream to form a first, second, and third interleaved stream with each stream formed by using a permutation of a same length K Π , wherein a permutation (π p0 ) used to form the second interleaved stream is the same as a permutation (π sys ) used to form the first interleaved stream and a permutation (π p1 ) used to form the third interleaved stream is different from π sys , and each element of π p1 is derived from the corresponding element of π sys ; bit-collection circuitry multiplexing the interleaved streams to form a circular buffer; and transmission circuitry transmitting bits from the circular buffer; wherein the bit-collection circuitry forms the circular buffer by: interlacing the interleaved second stream and interleaved third stream to form an intermediate stream; and concatenating the interleaved first stream with the intermediate stream.