Patent ID: 9413499
Filing Date: 2016-08-09
CPC Classification: H04B,H04J,H04L

Claim Text:
1. A code multiplexing transmission method in an orthogonal frequency division multiplexing (OFDM)-based radio access scheme, the method comprising: receiving information symbols of a plurality of sequences input in parallel; generating different spreading codes based on orthogonal code sequences; giving different phase rotation to the information symbols or the spreading codes for each symbol sequence and then, spreading the information symbols with the spreading codes for each symbol sequence; multiplexing spread information symbols corresponding to different symbol sequences; and placing the multiplexed spread information symbols on a frequency axis and performing Inverse Fast Fourier Transform (IFFT) on the multiplexed spread information symbols to output as an OFDM signal, wherein the information symbols or the spreading codes are rotated by a phase rotation amount for enabling overlaps in a signal constellation in polar coordinates of the spread information symbols for transmitting different information symbols to be controlled to within a required range, the multiplexed spread information symbols are assigned to frequencies respectively undergoing independent fading and are transmitted, and the orthogonal code sequences are generated by: wherein R W L: Length (spreading factor), L>0, and e: Euler number, e=2.7182818 . . . .