# US 2010/0166111 A1 · Method and apparatus for performing harq in wireless communication system

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- Number: US 2010/0166111 A1
- Document ID: US20100166111A1
- Status: Published application
- Kind: A1
- Application number: 12/638,961
- Filed: 2009-12-15
- Published: 2010-07-01
- Earliest claimed: 2008-12-16
- Assignees: LG Electronics Inc.
- Inventors: Hyung Ho Park; Jin Sam Kwak; Suk Woo Lee; Seung Hyun Kang
- Web page: https://patentgrep.com/patent/US20100166111A1

## CPC

- H04L 1/1819: {with retransmission of additional or different redundancy}
- H04L 1/0068: {by puncturing}
- H04L 1/1874: {Buffer management}
- H04L 1/1893: {Physical mapping arrangements (physical resource mapping in general H04L5/00)}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A method and an apparatus for performing hybrid automatic repeat request (HARQ) using constellation rearrangement and a circular buffer in a wireless communication system is provided. An encoded information bit is stored into a circular buffer. A transport block in selected from the circular buffer. A bit set comprising n bits of the transport block is mapped to a data symbol on a constellation for 2n-QAM modulation according to a first mapping order. The bit set is mapped according to a second mapping order when the bits of the transport block are subject to wrap-around at the end of the circular buffer.

## Claims

### Claim 1

A method of performing hybrid automatic repeat request (HARQ) in a wireless communication system, the method comprising:
storing an encoded information bit into a circular buffer;
selecting a transport block from the circular buffer; and
mapping a bit set comprising n bits of the transport block to a data symbol on a constellation for 2n-QAM modulation according to a first mapping order,
wherein the bit set is mapped according to a second mapping order when the bits of the transport block are subject to wrap-around at the end of the circular buffer.

### Claim 2 (depends on 1)

The method of claim 1, further comprising transmitting to a mobile station a constellation rearrangement version (CRV) for indicating a mapping order of the bit set, wherein the CRV is modified when the bits of the transport block are subject to wrap-around at the end of the circular buffer.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first mapping order is {b0, . . . , bn-1}, and the second mapping order is {bn-1, . . . , b0}.

### Claim 4 (depends on 1)

The method of claim 1, wherein n=4 or n=6.

### Claim 5 (depends on 1)

The method of claim 1, wherein the mapping to the data symbol comprises:
mapping a first bit set comprising n bits of the transport block to a first data symbol; and
mapping a second bit set comprising n bits of the transport block to a second data symbol.

### Claim 6 (depends on 5)

The method of claim 5, wherein, if the first bit set is {b0,b1,b2,b3} and the second bit set is {b4,b5,b6,b7}, the first mapping order is {b0,b1,b2,b3} and {b4,b5,b6,b7}, respectively, and the second mapping order is {b1,b4,b3,b6} and {b5,b0,b7,b2}, respectively.

### Claim 7 (depends on 5)

The method of claim 5, wherein, if the first bit set is {b0,b1,b2,b3,b4,b5} and the second bit set is {b6,b7,b8,b9,b10,b11}, the first mapping order is {b0,b1,b2,b3,b4,b5} and {b6,b7,b8,b9,b10,b11}, respectively, and the second mapping order is {b2,b7,b0,b5,b10,b3} and {b8,b1,b6,b11,b4,b9}, respectively.

### Claim 8

A method of performing hybrid automatic repeat request (HARQ) in a wireless communication system, the method comprising:
storing an encoded information bit into a circular buffer;
selecting a first transport block from the circular buffer;
mapping a bit set comprising n bits of the first transport block to a data symbol on a constellation for 2n-QAM modulation according to a first mapping order;
transmitting the data symbol of the first transport block;
receiving a retransmission request for the information bit;
selecting a second transport block for retransmission of the information bit from the circular buffer;
mapping a bit set comprising n bits of the second transport block to a data symbol on a constellation for 2n-QAM modulation; and
transmitting the data symbol of the second transport block,
wherein a bit set of the first transport block or the second transport block is mapped according to a second mapping order when bits of the first transport block or the second transport block are subject to wrap-around at the end of the circular buffer.

### Claim 9

A transmitter in a wireless communication system, the transmitter comprising:
a circular buffer configured to store an encoded information bit;
a mapper configure to select a transport block from the circular buffer and map a bit set comprising n bits of the transport block to a data symbol on a constellation for 2n-QAM modulation according to a first mapping order; and
a radio frequency (RF) unit coupled to the mapper,
wherein the mapper maps the bit set according to a second mapping order when the bits of the transport block are subject to wrap-around at the end of the circular buffer.