  The purpose of this study is to construct a near capacity Irregular Turbo
Code and to evaluate its performance over Gaussian channel. The methodology
used to evaluate and measure the performance of the new design is by simulating
the system by developing a software platform using Matlab. The simulation
carried out by implementing the system over different modulation schemes,
different frame sizes, and different code rates in order to achieve a fair
comparison between irregular turbo code and regular Turbo Code. The simulation
results showed that the Irregular Turbo Code with 64QAM modulation is capable
of achieving a coding gain of 1.29 dB over its corresponding Turbo Code for a
low Bit Error Rate 10 to 5, when used in a Gaussian noisy channel. Also, the
Irregular Turbo Code designed in this paper, utilizes a single recursive
Convolution encoder with short frame size of 5012 bits. The new designed codec
can play an important role in many commercial applications such as
Third-Generation wireless phones, Digital Video Broadcasting systems, or
Wireless Metropolitan Area Networks, etc.
