Code generator implementation on FPGA for an optical ZCZ code using a Sylvester type Hadamard matrix

The optical ZCZ code is a set of pairs of binary and bi-phase sequences with zero correlation zone. An optical code division multiple access (CDMA) system using this code can remove co-channel interference and influence of multi-path. We proposed the compact construction of a bank of matched filters for this code in a receiver. But we have not proposed the construction of a code generator for this code in a transmitter yet. In this paper, we propose the construction of two code generators for an optical ZCZ code using a Sylvester-type Hadamard matrix, which are called ROM-type and non ROM-type code generators. This ROM-type code generator can be constructed by a ROM and a up-counter. Similarly, this non ROM-type code generator can be constructed by a up-counter, flip-flops and logic gates. The ROM-type and non ROM-type code generators are implemented on a field programmable gate array (FPGA) corresponding to 400, 000 logic gates, and the non ROM-type code generator can reduce logic elements than the ROM-type code generator.