check matrix
1.A Parity check matrix is given for a systematic (12, 8) binary code which corrects all single errors and detects eight of the nine double adjacent errors within any of the three nibbles. Furthermore, it is shown that there can not exist a (12, 8) systematic binary code that corrects all single errors and detects all nine of the double adjacent errors within the three nibbles.
2.In B3G-system, the LDPC code has been used with the random irregular parity-check matrix, which the data length is 3944. The LDPC decoder, described in the Verilog HDL, has been implemented with Xilinx FPGA device Virtex-ⅡPro70. The maximum throughout of this decoder is 6.5 Mbps with 20 iterations.
3.It consists of a big keyboard of chinese characters,automatic phototypesetting machine and a check system consisting of a chinese character generator and a laser scanning dot-matrix printer. The chinese character generator is composed of 32×32 dot-matrix implemented with E-shape soft magnetic-core.
