Frequency domain partial response signaling with high spectral efficiency and low peak to average power ratio
AssigneeNokia Corporation
InventorVenkatesh Vadde
Life of this patent
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Abstract
The system includes a transmitter for generating a signal in the time domain and transforming the signal to the frequency domain, wherein the transmitter suppresses a plurality of sub-carriers of the signal, The resulting truncated signal is transmitted to the receiver through a noisy channel. The receiver receives a noisy signal and recovers the carrier signal and, hence, the partial response signal from the noisy signal. The method includes selecting a cyclic convolver having predefined values, applying the cyclic convolver to a signal to produce a partial response signal, dropping a plurality of sub-carriers of the partial response signal, to generate a modulated carrier signal that is ready for transmission.
Claims20
A communication system comprising:
- a transmitter for generating a signal, wherein the signal is generated from a partial response signal produced from mapping an input bit stream to a complex number domain and wherein the transmitter transforms a stream of symbols in the time domain to a set of frequency domain subcarriers and suppresses a plurality of sub-carriers having power less than a threshold amount;
- a receiver in communication with the transmitter through a channel for receiving a signal, wherein the receiver recovers the signal by a sequence-detection mechanism in the time domain.
A mobile station in a cellular communication system comprising:
- a transmitter for generating and sending to a base station a signal, wherein the signal is generated from a partial response signal produced from mapping an input bit stream to a complex number domain and wherein the transmitter transforms a stream of symbols in the time domain to a set of frequency domain subcarriers and suppresses a plurality of sub-carriers having power less than a threshold amount;
- and
- a receiver for receiving a signal from said base station through a channel for receiving a signal, wherein the receiver recovers the signal by a sequence-detection mechanism in the time domain.
A method for increasing bit-rate through effective bandwidth gain in a system utilizing an orthogonal frequency division multiplexing technique, the method comprising:
- selecting a cyclic convolver having predefined values;
- applying the cyclic convolver to a time-domain signal having a plurality of sub-symbols to produce a partial response signal having the plurality of sub-symbols, wherein the values of the cyclic convolver are selected such that a portion of the Fourier transform of the plurality of sub-symbols of the partial response signal are reduced to near zero amplitude;
- dropping the portion of the Fourier transform of the plurality of sub-symbols with near zero amplitude from the partial response signal to produce a truncated partial response signal;
- and
- appending a cyclic prefix at a leading edge of the truncated partial response signal.
Dependencies are inferred from the claim text.