Frequency domain partial response signaling with high spectral efficiency and low peak to average power ratio

1. 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 a 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 in communication with the transmitter through a channel for receiving a signal, wherein the receiver recovers the received signal by a sequence-detection mechanism in the time domain.

2. 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 a 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 in communication with the transmitter through a channel for receiving a signal, wherein the receiver recovers the received signal by a sequence-detection mechanism in the time domain wherein the transmitter comprises:

a mapping unit for mapping the input bit stream in the time domain to a set of sub-symbols;

a cyclic convolver unit coupled to the mapping unit for generating the partial response signal;

a unit for transforming the stream of symbols to said set of frequency domain subcarriers;

a spectral compression unit for deleting selected subcarriers; and

an inverse transforming unit for transforming the set of frequency domain subcarriers to the time domain.

3. The system of claim 2 , in which said spectral compression unit deletes an equal number of subcarriers at least one extremity of the set of frequency domain subcarriers.

4. The system of claim 3 , in which said spectral compression unit deletes subcarriers carrying energy less than a threshold at the extremities of the set of frequency domain subcarriers.

5. 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 a 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 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 in which a spectral compression unit deletes an equal number of subcarriers at the extremities of the set of frequency domain subcarriers.

6. The system of claim 5 , in which said spectral compression unit deletes subcarriers carrying energy less than a threshold at the extremities of the set of frequency domain subcarriers.

7. 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 a 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 in communication with the transmitter through a channel for receiving a signal, wherein the receiver recovers the received signal by a sequence-detection mechanism in the time domain in which said transmitter comprises at least one phase-modulated constant envelope amplifier.

8. The system of claim 7 , wherein the transmitter comprises:

a mapping unit for mapping the input bit stream in the time domain to a set of sub-symbols;

a cyclic convolver unit coupled to the mapping unit for generating a the partial response signal;

a unit for transforming the stream of symbols to said set of frequency domain subcarriers; and

a spectral compression unit for deleting selected subcarriers; and an inverse transforming unit for transforming the set of frequency domain subcarriers to the time domain.

9. The system of claim 8 , in which said spectral compression unit deletes an equal number of subcarriers at the extremities of the set of frequency domain subcarriers.

10. The system of claim 9 , in which said spectral compression unit deletes subcarriers carrying energy less than a threshold at the extremities of the set of frequency domain subcarriers.

11. The system of claim 7 , in which a spectral compression unit deletes an equal number of subcarriers at the extremities of the set of frequency domain subcarriers.

12. The system of claim 11 , in which said spectral compression unit deletes subcarriers carrying energy less than a threshold at the extremities of the set of frequency domain subcarriers.

13. A mobile station comprising:

a transmitter means for generating and sending a signal to a remote receiver, 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 a 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 a remote transmitter through a channel, wherein the receiver recovers the received signal by a sequence-detection mechanism in the time domain.

14. The mobile station of claim 13 , wherein the transmitter comprises:

a mapping unit for mapping the input bit stream in the time domain to a set of sub-symbols;

a cyclic convolver unit coupled to the mapping unit for generating the partial response signal;

a unit for transforming the stream of symbols to said set of frequency domain subcarriers;

a spectral compression unit for deleting selected subcarriers; and

an inverse transforming unit for transforming the set of frequency domain subcarriers to the time domain.

15. The mobile station of claim 14 , in which said spectral compression unit deletes an equal number of subcarriers at the extremities of the set of frequency domain subcarriers.

16. The mobile station of claim 15 , in which said spectral compression unit deletes subcarriers carrying energy less than a threshold at the extremities of the set of frequency domain subcarriers.

17. The mobile station of claim 13 , in which a spectral compression unit deletes an equal number of subcarriers at the extremities of the set of frequency domain subcarriers.

18. 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 a Fourier transform of the plurality of sub-symbols of the partial response signal is 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.

19. The method of claim 18 , further comprising:

transforming the partial response signal using a fourier transformation technique to produce a signal in a frequency domain;

transmitting the frequency domain signal through a noisy channel to produce a noisy signal;

and recovering a time based signal from the noisy signal at a receiver.