TRANSMITTING APPARATUS AND METHOD USING TONE RESERVATION IN OFDM SYSTEM

• US 20090304097A1
• Filed: 01/24/2007
• Published: 12/10/2009
• Est. Priority Date: 01/24/2006
• Status: Abandoned Application

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Ki Jun, Yun, Young Woo, Noh, Min Seok, Han, Seung Hee, Kwon, Yeong Hyeon
• Application Number:
  US12/161,947
• Publication Number:
  US 20090304097A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 27/2618 Reduction thereof using auxiliary subcarriers

Abstract

The present invention relates to an apparatus and a method for transmitting orthogonal frequency division multiplexing (OFDM) signals using a tone reservation scheme. Preferably, the present invention comprises an inserter to add a transmit format indicator (TFI) to an encoded packet, the TFI including a tone reservation rate for a peak to average power ratio (PAPR) control; a reordering module to change order of bits included in the encoded packet by discriminating information bits and parity bits of the encoded packet; a zero replacement module to replace a portion of the parity bits with at least one bit set for a PAPR control;’ a transmitter to transmit the replaced output using a plurality of orthogonal sub-carriers; and a controller to control the tone reservation rate based on status of received signals.

Claims

1. An apparatus for transmitting orthogonal frequency division multiplexing (OFDM) signals using a tone reservation scheme, the apparatus comprising:

an inserter to add a transmit format indicator (TFI) to an encoded packet, the TFI including a tone reservation rate for controlling a peak to average power ratio (PAPR);

a reordering module to change order of bits included in the encoded packet by discriminating information bits and parity bits of the encoded packet;

a zero replacement module to replace a portion of the parity bits with at least one bit set for controlling the PAPR;

a transmitter to transmit the replaced output using a plurality of orthogonal sub-carriers; and

a controller to control the tone reservation rate based on status of received signals.

2. The apparatus of claim 1, wherein the transmitter includes a gradient algorithm module to control the PAPR using signals which have a property of an impulse signal.

3. The apparatus of claim 1, wherein the tone reservation rate has a higher value when the status of the received signals is poor.

4. The apparatus of claim 1, wherein the controller includes a memory which saves the tone reservation rate corresponding to quantized status of the received signals.

5. The apparatus of claim 4, wherein a location for tones corresponding to a higher tone reservation rate includes a location for tones corresponding to a lower tone reservation rate.

6. The apparatus of claim 4, wherein the tone reservation rate is one of 0%, 5%, 10% and 20%.

7. A method of transmitting orthogonal frequency division multiplexing (OFDM) signals using a tone reservation scheme, the method comprising,

acquiring information regarding reception status of received signals;

and

transmitting the OFDM signals by sub-carriers corresponding to a total bandwidth,

wherein the sub-carriers include at least one sub-carrier allocated by a transmitter for controlling a peak to average power ratio (PAPR), and the at least one sub-carrier is allocated based on a tone reservation rate corresponding to the reception status of received signals.

8. The method of claim 7, wherein the tone reservation rate is decreased when the reception status of received signals is good.

9. The method of claim 8, wherein the transmitted OFDM signals include a transmit format indicator (TFI) corresponding to the tone reservation rate.

10. The method of claim 7, wherein the step of transmitting includes controlling the PAPR of the OFDM signals using a gradient algorithm according to the tone reservation rate.