Apparatus and method for reducing peak to average ratio in wireless communication system
The purpose of the present invention is to reduce the Peak-to-Average Ratio (PAR) of a transmission signal. A transmission device includes a generation part for generating a cancellation pulse corresponding to a peak component of a transmission signal, and a cancellation part for attenuating the peak component using the cancellation pulse. In addition, the present invention includes some embodiments other than the aforesaid embodiment.
1. A method for operating a transmission device in a wireless communication system, the method comprising:
detecting a first peak and a second peak of an original signal;
generating, based on a complex gain of the first peak of the original signal, a first portion of a first cancelling pulse for attenuating the first peak;
storing coefficients corresponding to the first portion of the first cancelling pulse in an order;
generating a second portion of the first cancelling pulse by outputting the stored coefficients in a reverse order with respect to the order, during a process in which coefficients corresponding to a first portion of a second cancelling pulse for attenuating the second peak are stored; and
generating a transmission signal by applying the first cancelling pulse and the second cancelling pulse to the original signal.
2. The method of claim 1 , wherein detecting the first peak and the second peak comprises:
receiving the original signal; and
detecting the first peak and the second peak of the original signal by comparing a value of magnitude for the original signal and a threshold value.
3. The method of claim 2 , wherein generating the first portion of the first cancelling pulse comprises:
determining the complex gain based on the magnitude of the detected first peak of the original signal; and
multiplying the complex gain by a base waveform including a plurality of samples with coefficients.
4. The method of claim 2 , wherein the complex gain is proportional to the magnitude of the first peak.
5. The method of claim 1 , wherein the first cancelling pulse is divided into the first portion and the second portion at a maximum value,
wherein the second portion is a portion of the first cancelling pulse, except for the first portion of the first cancelling pulse,
wherein the first portion of the first cancelling pulse is followed by the second portion of the first cancelling pulse, and
wherein the second portion of the first cancelling pulse is identical to a conjugate of the first portion of the first cancelling pulse.
6. An apparatus for a transmission device in a wireless communication system, the apparatus comprising:
at least one memory;
a peak detector configured to detect a first peak and a second peak of an original signal;
a generator configured to:
generate, based on a complex gain of the first peak of the original signal, a first portion of a first cancelling pulse for attenuating the first peak,
store coefficients corresponding to the first portion of the first cancelling pulse in an order, and
generate a second portion of the first cancelling pulse by outputting the stored coefficients in a reverse order with respect to the order during a process in which coefficients corresponding to a first portion of a second cancelling pulse for attenuating the second peak is stored; and
a cancelling unit, which includes at least one subtractor, configured to generate a transmission signal by applying the first cancelling pulse and the second cancelling pulse to the original signal.
7. The apparatus of claim 6 , wherein the peak detector is further configured to:
receive the original signal; and
detect the first peak and the second peak of the original signal by comparing a value of magnitude for the original signal and a threshold value.
8. The apparatus of claim 7 , wherein the generator is further configured to:
determine the complex gain based on the magnitude of the detected first peak of the original signal; and
multiply the complex gain by a base waveform including a plurality of samples.
9. The apparatus of claim 7 , wherein the complex gain is proportional to the magnitude of the first peak.
10. The apparatus of claim 6 , wherein the first cancelling pulse is divided into the first portion and the second portion at a maximum value,
wherein the second portion is a portion of the first cancelling pulse, except for the first portion of the first cancelling pulse,
wherein the first portion of the first cancelling pulse is followed by the second portion of the first cancelling pulse, and
wherein the second portion of the first cancelling pulse is identical to a conjugate of the first portion of the first cancelling pulse.