Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Multilevel LDPC Codes Design for Multimedia Communication CDMA System | EURASIP Journal on Wireless Communications and Networking 2004 1 141-148 2004 Hindawi Publishing Corporation Multilevel LDPC Codes Design for Multimedia Communication CDMA System Jia Hou Institute of Information and Communication Chonbuk National University Chonju 561-756 Korea Em ail jiahou@ YuYi Institute of Information and Communication Chonbuk National University Chonju 561-756 Korea Email yuyi@ Moon Ho Lee Institute of Information and Communication Chonbuk National University Chonju 561-756 Korea Email moonho@ Received 25 October 2003 Revised 25 February 2004 We design multilevel coding MLC with a semi-bit interleaved coded modulation BICM scheme based on low density parity check LDPC codes. Different from the traditional designs we joined the MLC and BICM together by using the Gray mapping which is suitable to transmit the data over several equivalent channels with different code rates. To perform well at signal-to-noise ratio SNR to be very close to the capacity of the additive white Gaussian noise AWGN channel random regular LDPC code and a simple semialgebra LDPC SA-LDPC code are discussed in MLC with parallel independent decoding PID . The numerical results demonstrate that the proposed scheme could achieve both power and bandwidth efficiency. Keywords and phrases multilevel coding BICM LDPC PID. 1. INTRODUCTION In the next generation of code division multiple access CDMA system the primary challenge is high-quality and high data rate multimedia communication. Normally the mobile transmission systems deal with various kinds of information such as voice data and images. The volume of traffic required is therefore far higher than current voice or data-based applications. This increase in traffic rates is expected to become even more serious when full interactive multimedia transfers are required. As the information volume increases so does the required instantaneous transmission rate. Table 1 shows an estimate of
