Patent ID: 9363123
Filing Date: 2016-06-07
CPC Classification: H04L

Claim Text:
1. A method for conditioning an orthogonal frequency division multiplex (OFDM) signal prior to transmission by a transmitter in an orthogonal frequency division multiple access (OFDMA) system operating on a channel with a plurality of subcarriers grouped into subchannels, the method comprising: clipping said OFDM signal in the time domain to produce a clipped-off portion of said OFDM signal, wherein a time sample of the clipped-off portion of the said OFDM signal is set to zero if a corresponding time sample of the OFDM signal is not greater than a threshold that is based on a desired peak-to-average-power ratio (PAPR); transforming said clipped-off portion of said OFDM signal to produce a frequency-domain signal; applying an in-band spectral shaping mask to individual subcarriers or subchannels of the frequency-domain signal within the channel to control levels of in-band distortion on the individual subcarriers or subchannels, wherein a different in-band distortion level is allowed for a different subcarrier or subchannel; transforming the shaped frequency-domain signal to produce a time-domain signal; and producing a conditioned signal for transmission by subtracting the time-domain signal from said OFDM signal.