Block Codes

In general a store like it's still exist and it is necessary for developing a strategy and management. The strategy is meant by increasing the quality of marketing , management, service and others including the application of information teknology in it. Based on observation and interviews, information system affects many aspects, including aspects of the sale is still conventional system usually only use the book to back up sales data and a written memorandum clerk. Officers cashier often make mistakes when many consumers come together. Thus the problems created for compulterized information system sales that will make more efficient and accurate sales data. With the sale information system can assist the cashier in the process of seling data management more efficient and accurate. 1. PENDAHULUAN a. Latar Belakang Kasir adalah tempat melakukan transaksi / pembayaran yang menjadi akhir dari sebuah transaksi jual beli antar konsumen dan produsen sehingga menghasilkan kepuasan pada masing masing pihak Kasir juga dapat di artikan sebagai pintu pertama dan terakhir di setiap transaksi yang terjadi di toko. Jika mempunyai pramuniaga yang sopan, melayani konsumen dengan tulus, ternyata setelah konsumen melakukan pembayaran kasirnya kurang ramah, kurang sopan sehingga menyebabkan kebanyakan dari pengunjung tidak mau kembali lagi ke toko anda lagi. Lain halnya jika anda mempunyai pramuniaga yang kurang cakap cenderung kurang sopan kepada konsumen tapi di imbangi dengan

OFDM with Quadrature amplitude modulation (QAM) technique can be used for high speed optical applications. As the order of modulation increases, the bit error rate (BER) increases. Forward Error correction (FEC) coding like LDPC coding is generally used to Improve BER performance. LDPC provides large minimum distance and also the power efficiency of the LDPC code increases significantly with the code length. Here we have given a theoretical review on the design of encoder and decoder for the Block codes followed by the fundamentals of various modified Block codes. Finally using a long Irregular LDPC code, it is shown that LDPC coded OFDM provides very low bit error rate compared to OFDM without coding case with a gain in transmitter power and thus making the link power efficient.