APPARATUS FOR GENERATING LAYERED ORTHOGONAL CODES

PURPOSE: An apparatus for generating layered orthogonal codes is provided to optimize a modem by generating the layered orthogonal codes to implement a low complex modulating block and a low complex demodulating block. CONSTITUTION: An apparatus for generating layered orthogonal codes comprises a binary.sup.n counter(11), a bit shifter(12), a bit reverse(13), and a logical operator(17). The binary.sup.n counter performs a counting process on the basis of an assortment number maximum value n(n is a natural number) of a generating code, according to an external clock. The bit shifter shifts an external code number as a n-code assortment number, according to an external code assortment number. The bit reverse receives an output of the bit shifter, and reverses an order of a most significant bit(MSB) and a least significant bit(LSB). The logical operator logically operates a n bit output of the binary.sup.n counter and a n bit output of the bit reverse, and generates orthogonal codes. The logical operator comprises a n bit AND gate(14), a tree-structured exclusive XOR gate(15), and an inverter(16). The n bit AND gate applies AND gates to input signals of the binary.sup.n counter and the bit reverse according to bits. The tree-structured exclusive XOR gate sequentially applies exclusive XOR gates to bits outputted from the n bit AND gate. The inverter reverses an outputted bit value of the exclusive XOR gate, and generate the orthogonal codes to output the codes.