Method of reducing papr in multiple antenna ofdm communication system and multiple antenna ofdm communication system using the method

• US 20060262714A1
• Filed: 02/13/2004
• Published: 11/23/2006
• Est. Priority Date: 02/17/2003
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Chan-Soo, Tarokh, Vahid, Kim, Yung-Soo, Chung, Jae-Hak
• Application Number:
  US10/546,081
• Publication Number:
  US 20060262714A1
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 27/2615 Reduction thereof using coding
• CPC Class Codes: H04L 27/2623 Reduction thereof by clipping

Abstract

Provided is a method of reducing a peak-to-average-power ratio in a multiple antenna orthogonal frequency division multiplexing communication system. The method includes: reducing a peak-to-average-power ratio of input serial data sequences; space-time coding the input serial data sequences with the reduced peak-to-average-power ratio to generate N symbols to be tranmitted via N antennas; receiving the serial data sequences of the N symbols to transform the serial data sequences into N parallel data sequences; allocating each of the N parallel data sequences to Ns sub-carriers and performing Inverse Fast Fourier Transform on the N parallel data sequences; transforming the N parallel data sequences into N serial data symbols; and replicating a portion of the serial data symbols to generate cyclic prefixes and interleaving the cyclic prefixes into starting portions of the serial data symbols to cyclically expand the N symbols.

Claims

1. A method of reducing a peak-to-average-power ratio in a multiple antenna orthogonal frequency division multiplexing communication system, the method comprising:

reducing a peak-to-average-power ratio of input serial data sequences;

space-time coding the input serial data sequences with the reduced peak-to-average-power ratio to generate N symbols to be transmitted via N antennas;

receiving the serial data sequences of the N symbols to transform the serial data sequences into N parallel data sequences;

allocating each of the N parallel data sequences to N_s sub-carriers and performing Inverse Fast Fourier Transform on the N parallel data sequences;

transforming the N parallel data sequences into N serial data symbols; and

replicating a portion of the serial data symbols to generate cyclic prefixes and interleaving the cyclic prefixes into starting portions of the serial data symbols to cyclically expand the N symbols.

2. The method of claim 1, wherein the peak-to-average-power ratio of the input serial data sequences is reduced using a signal distorting scheme comprising clipping, peak windowing, and peak cancellation.

3. The method of claim 1, wherein the peak-to-average-power ratio of the input serial data sequences is reduced using a scrambling scheme.

4. The method of claim 1, wherein the peak-to-average-power ratio of the input serial data sequences is reduced using Golay complementary codes.

5. The method of claim 1, wherein the N symbols are generated using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$\mathrm{QPSK}=\frac{\sqrt{2}}{2}<br><br>\mathrm{BPSK}+j<br><br>\frac{\sqrt{2}}{2}<br><br>\mathrm{BPSK}$

6. The method of claim 1, wherein the N symbols are generated using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$8-\mathrm{QAM}=\frac{\sqrt{2}}{5}<br><br>\mathrm{BPSK}+j<br><br>\frac{\sqrt{2}}{5}<br><br>\mathrm{BPSK}+{\mathrm{e<br><br>}}^{-j<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}/4}<br><br>\sqrt{\frac{1}{5}}<br><br>\mathrm{BPSK}$

7. The method of claim 5, wherein the N symbols are generated using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$16-\mathrm{QAM}=\frac{\sqrt{2}}{5}<br><br>\mathrm{QPSK}+j<br><br>\frac{1}{\sqrt{5}}<br><br>\mathrm{QPSK}$

8. The method of claim 7, wherein the N symbols are generated using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$64-\mathrm{QAM}=\sqrt{\frac{16}{21}}<br><br>\mathrm{QPSK}+j<br><br>\sqrt{\frac{5}{21}}<br><br>16-\mathrm{QAM}$

9. A multiple antenna orthogonal frequency division multiplexing communication system comprising:

a space-time coder that space-time codes input serial data sequences to generate N symbols to be transmitted via N antennas;

a peak-to-average-power ratio reducer that reduces a peak-to-average-power ratio of the serial data sequences of the N symbols;

a serial-to-parallel transformer that receives the serial data sequences of the N symbols with the reduced peak-to-average-power ratio to transform the serial data sequences into N parallel data sequences;

an Inverse Fast Fourier Transform unit that allocates each of the N parallel data sequences to N_s sub-carriers and performs Inverse Fast Fourier Transform on the N parallel data sequences;

a parallel-to-serial transformer that transforms the N parallel data sequences into N serial data symbols;

a cyclic prefix interleaver that replicates a portion of the serial data symbols to generate cyclic prefixes and interleaves the cyclic prefixes into starting portions of the serial data symbols to cyclically expand the N symbols.

10. The multiple antenna orthogonal frequency division multiplexing communication system of claim 9, wherein the peak-to-average-power ratio reducer reduces the peak-to-average-power ratio of the input serial data sequences using a signal distorting scheme comprising clipping, peak windowing, and peak cancellation.

11. The multiple antenna orthogonal frequency division multiplexing communication system of claim 9, wherein the peak-to-average-power ratio reducer reduces the peak-to-average-power ratio of the input serial data sequences using a scrambling scheme.

12. The multiple antenna orthogonal frequency division multiplexing communication system of claim 9, wherein the peak-to-average-power ratio reducer reduces the peak-to-average-power ratio of the input serial data sequences using Golay complementary codes.

13. The multiple antenna orthogonal frequency division multiplexing communication system of claim 9, wherein the space-time coder generates the N symbols using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$\mathrm{QPSK}=\frac{\sqrt{2}}{2}<br><br>\mathrm{BPSK}+j<br><br>\frac{\sqrt{2}}{2}<br><br>\mathrm{BPSK}$

14. The multiple antenna orthogonal frequency division multiplexing communication system of claim 9, wherein the space-time coder generates the N symbols using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$8-\mathrm{QAM}=\frac{\sqrt{2}}{5}<br><br>\mathrm{BPSK}+j<br><br>\frac{\sqrt{2}}{5}<br><br>\mathrm{BPSK}+{\mathrm{e<br><br>}}^{-j<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}/4}<br><br>\sqrt{\frac{1}{5}}<br><br>\mathrm{BPSK}$

15. The multiple antenna orthogonal frequency division multiplexing communication system of claim 13, wherein the space-time coder generates the N symbols using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$16-\mathrm{QAM}=\frac{\sqrt{2}}{5}<br><br>\mathrm{QPSK}+j<br><br>\frac{1}{\sqrt{5}}<br><br>\mathrm{QPSK}$

16. The multiple antenna orthogonal frequency division multiplexing communication system of claim 15, wherein the space-time coder generates the N symbols using a 2^m-PSK with a low peak-to-average-power ratio and a code obtained from Equation below:

$64-\mathrm{QAM}=\sqrt{\frac{16}{21}}<br><br>\mathrm{QPSK}+j<br><br>\sqrt{\frac{5}{21}}<br><br>16-\mathrm{QAM}$