New European Patent: Reducing out-of-band emission
European Patent Application No. 11846063.3, as part of CSIRO Ngara backhaul IP portfolio which bring wireless broadband communications to rural and regional Australia.
About this Patent
Discrete Fourier transform-orthogonal frequency-division multiplexing transmitter for use in communication system to transmit symbol sequence over communication channel, has conversion module to convert symbol to analog waveform
The transmitter (200) has a sidelobe suppression module (210) provided to apply a suppression matrix to an input vector. A modulation module (220) modulates a precoded vector to a time-domain symbol by utilizing multiple sub-carriers. A digital-to-analog conversion module (240) converts the symbol to an analog waveform for transmission, where the suppression matrix is constructed such that emissions at a predetermined suppression distance lying outside a frequency band defined by the sub-carriers are set to zero according to a predetermined emission model.
Discrete Fourier transform-orthogonal frequency-division multiplexing (DFT-OFDM) transmitter for use in a multicarrier communication system i.e. precoding OFDM system, which is utilized in broadband communication industries, for transmitting a symbol sequence over a communication channel.
Advantages of Use
The transmitter improves spectral efficiency and power efficiency so as to achieve better balance for sidelobe suppression performance. The sidelobe suppression module reduces sidelobe power by multiplying vector symbols input to the sidelobe suppression module by a suppression matrix to obtain a signal vector, so that the actual emissions at the suppression distances are not exactly zero, and the different constructions of the suppression matrix reduce out-of-band emission.