Apparatus and method for retransmitting high-speed data in a CDMA mobile communication system

• US 20030021240A1
• Filed: 07/25/2002
• Published: 01/30/2003
• Est. Priority Date: 07/25/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Moon, Yong-Suk, Kim, Hun-Kee, Yoon, Jae-Seung, Choi, Gin-Kyu
• Granted Patent: US 7,283,509 B2
• Time in Patent Office: Days
• US Class Current: 370/320
• CPC Class Codes: H04B 7/2631 for broadband transmission
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/1816 with retransmission of the same, encoded, message
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00

Abstract

An apparatus for retransmitting data at a retransmission request from a receiver by a transmitter in a CDMA mobile communication system including a turbo encoder with a given coding rate and initially transmitting systematic bits and parity bits obtained by encoding the data by the turbo encoder using one modulation mode among a plurality of modulation modes. A controller determines a modulation mode to be used between the transmitter and the receiver in response to the retransmission request. A distributor distributes coded bits obtained by encoding the data at the coding rate into systematic bits and parity bits. A selector selects coded bits transmittable by the determined modulation mode among the systematic bits and the parity bits at the initial transmission, if the determined modulation mode is different from the modulation mode used at initial transmission. A modulator modulates the transmittable coded bits into modulated symbols according to the determined modulation mode.

Claims

1. A method for retransmitting data at a retransmission request from a receiver by a transmitter in a CDMA (Code Division Multiple Access) mobile communication system including a turbo encoder with a given coding rate and initially transmitting systematic bits and parity bits obtained by encoding the data by the turbo encoder using one modulation mode among a plurality of modulation modes, the method comprising the steps of:

determining a modulation mode to be used between the transmitter and the receiver in response to the retransmission request;

distributing coded bits obtained by encoding the data at the coding rate into systematic bits and parity bits; and

if the determined modulation mode is different from the modulation mode used at initial transmission, modulating into modulated symbols coded bits transmittable by the determined modulation mode among the systematic bits and the parity bits at the initial transmission, and transmitting the modulated symbols.

2. The method of claim 1, wherein the modulation mode to be used at retransmission is determined according to a variation in a channel environment.

3. The method of claim 1, wherein the systematic bits are first selected as the transmittable coded bits.

4. The method of claim 1, wherein previously non-retransmitted systematic bits or previously non-retransmitted parity bits among the systematic bits and the parity bits are first selected as the transmittable coded bits.

5. The method of claim 1, wherein the systematic bits are first repeatedly selected along with the systematic bits and the parity bits as the transmittable code bits.

6. The method of claim 1, wherein previously non-retransmitted systematic bits or previously non-retransmitted parity bits are first repeatedly selected along with the systematic bits and the parity bits as the transmittable coded bits.

7. The method of claim 1, wherein the systematic bits are separated into a plurality of systematic sub-packets and the parity bits are separated into a plurality of parity sub-packets, in order to select the transmittable coded bits in a unit of the systematic sub-packet or the parity sub-packet.

8. An apparatus for retransmitting data at a retransmission request from a receiver by a transmitter in a CDMA (Code Division Multiple Access) mobile communication system including a turbo encoder with a given coding rate and initially transmitting systematic bits and parity bits obtained by encoding the data by the turbo encoder using one modulation mode among a plurality of modulation modes, the apparatus comprising:

a controller for determining a modulation mode to be used between the transmitter and the receiver in response to the retransmission request;

a distributor for distributing coded bits obtained by encoding the data at the coding rate into systematic bits and parity bits;

a selector for selecting coded bits transmittable by the determined modulation mode among the systematic bits and the parity bits at the initial transmission, if the determined modulation mode is different from the modulation mode used at initial transmission; and

a modulator for modulating the transmittable coded bits into modulated symbols according to the determined modulation mode.

9. The apparatus of claim 8, wherein the modulation mode to be used at retransmission is determined according to a variation in a channel environment.

10. The apparatus of claim 8, wherein the selector first selects the systematic bits as the transmittable coded bits.

11. The apparatus of claim 8, wherein the selector first selects previously non-retransmitted systematic bits or previously non-retransmitted parity bits among the systematic bits and the parity bits, as the transmittable coded bits.

12. The apparatus of claim 8, wherein the selector first repeatedly selects the systematic bits along with the systematic bits and the parity bits as the transmittable code bits.

13. The apparatus of claim 8, wherein the selector first repeatedly selects previously non-retransmitted systematic bits or previously non-retransmitted parity bits along with the systematic bits and the parity bits, as the transmittable coded bits.

14. The apparatus of claim 8, wherein the selector separates the systematic bits into a plurality of systematic sub-packets, separates the parity bits into a plurality of parity sub-packets, and selects the transmittable coded bits in a unit of the systematic sub-packet or the parity sub-packet.

15. A method for receiving modulated symbols retransmitted by a transmitter according to a modulation mode different from a modulation mode used at initial transmission in a CDMA (Code Division Multiple Access) mobile communication system including a turbo encoder with a given coding rate and initially transmitting systematic bits and parity bits obtained by encoding data by the turbo encoder as modulated symbols using one modulation mode among a plurality of modulation modes, the method comprising the steps of:

demodulating the modulated symbols according to a demodulation mode corresponding to the modulation mode used by the transmitter at retransmission, and outputting coded bits distributing the coded bits into systematic packets comprised of the systematic bits and parity packets comprised of the parity bits;

combining the systematic packets with previously received systematic packets, and combining the parity packets with previously received parity packets; and

decoding the combined systematic packets and the combined parity packets into information bits.

16. The method of claim 15, wherein the modulation mode to be used at retransmission is determined according to a variation in a channel environment.

17. The method of claim 15, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and the initially transmitted systematic bits are first selected as the retransmitted coded bits.

18. The method of claim 15, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and previously non-retransmitted systematic bits or previously non-retransmitted parity bits among the initially transmitted systematic bits and the initially transmitted parity bits are first selected as the transmittable coded bits.

19. The method of claim 15, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and the systematic bits are first repeatedly selected along with the initially transmitted systematic bits and the initially transmitted parity bits as the transmittable code bits.

20. The method of claim 15, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and previously non-retransmitted systematic bits or previously non-retransmitted parity bits are first repeatedly selected along with the initially transmitted systematic bits and the initially transmitted parity bits as the transmittable coded bits.

21. The method of claim 15, wherein the systematic packets each are comprised of a plurality of systematic sub-packets and the parity packets each are comprised of a plurality of parity sub-packets.

22. An apparatus for receiving modulated symbols retransmitted by a transmitter according to a modulation mode different from a modulation mode used at initial transmission in a CDMA (Code Division Multiple Access) mobile communication system including a turbo encoder with a given coding rate and initially transmitting systematic bits and parity bits obtained by encoding data by the turbo encoder as modulated symbols using one modulation mode among a plurality of modulation modes, the apparatus comprising:

a demodulator for demodulating the modulated symbols according to a demodulation mode corresponding to the modulation mode used by the transmitter at retransmission, and outputting coded bits;

a packet distributor for distributing the coded bits into systematic packets comprised of the systematic bits and parity packets comprised of the parity bits;

a combiner for combining the systematic packets with previously received systematic packets, and combining the parity packets with previously received parity packets; and

a decoder for decoding the combined systematic packets and the combined parity packets into information bits.

23. The apparatus of claim 22, wherein the modulation mode to be used at retransmission is determined according to a variation in a channel environment.

24. The apparatus of claim 22, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and the initially transmitted systematic bits are first selected as the retransmitted coded bits.

25. The apparatus of claim 22, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and previously non-retransmitted systematic bits or previously non-retransmitted parity bits among the initially transmitted systematic bits and the initially transmitted parity bits are first selected as the transmittable coded bits.

26. The apparatus of claim 22, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and the systematic bits are first repeatedly selected along with the initially transmitted systematic bits and the initially transmitted parity bits as the transmittable code bits.

27. The apparatus of claim 22, wherein the retransmitted coded bits are identical to coded bits transmittable by the modulation mode used at retransmission, and previously non-retransmitted systematic bits or previously non-retransmitted parity bits are first repeatedly selected along with the initially transmitted systematic bits and the initially transmitted parity bits as the transmittable coded bits.

28. The apparatus of claim 22, wherein the systematic packets each are comprised of a plurality of systematic sub-packets and the parity packets each are comprised of a plurality of parity sub-packets.