| 摘要 |
<p>An apparatus for improving spectral efficiency of OFDMA(Orthogonal Frequency Division Multiplexing Access) and method thereof are provided to increase data quantity transmitted per hour by transmitting an additional data in not only a frequency domain but also a time domain. An apparatus for improving spectral efficiency of OFDMA comprises a serial-to-parallel converter, a specific filter(IN-J), a pilot signal input unit, a reverse fast fourier transform unit, a parallel-to-serial converter, an addition data generator, a specific filter(IN-Jadd), a signal combiner, and a cyclic prefix adder. The serial-to-parallel converter parallel converts a serial data for transmitting in a frequency domain(501). The specific filter(IN-J) filters a data converted in the serial-to-parallel converter in order to maintain orthogonality with data added in a time domain(503). The pilot signal input unit synthesizes a pilot signal in data filtered in the specific filter(IN-J). The reverse fast fourier transform unit converts a synthesized frequency domain signal into the time domain signal(507). The parallel-to-serial converter serially converts a parallel inputted symbols of a transformed time domain signal(509). The addition data generator additionally generates a time domain data in the time domain(511). The specific filter(IN-Jadd) filters an additionally generated time domain data(513). The signal combiner synthesizes the additionally generated time domain data with the time domain signal(515). The cyclic prefix adder adheres CP(Cyclic Prefix) to a summation result, and transmits(517).</p> |
