Method for physical layer automatic repeat request for a base station

• US 20030039227A1
• Filed: 02/27/2002
• Published: 02/27/2003
• Est. Priority Date: 08/24/2001
• Status: Active Grant

• Current Assignee: Joseph A. Kwak
• Original Assignee: Joseph A. Kwak
• Inventors: Kwak, Joseph A.
• Granted Patent: US 7,672,265 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0034 where the transmitter decides based on inferences, e.g. use of implicit signalling
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 2001/0096 Channel splitting in point-to-point links
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A physical automatic repeat request method implemented by a base station having a transmitter and a receiver. A physical layer, at the transmitter receives data and formats the received data into packets having a particular encoding/data modulation. The physical layer transmit the packets and retransmits packets upon failure to receive a corresponding acknowledgment for a given packet. An adaptive modulation and coding controller in the transmitter collects retransmission statistics and adjusts the particular encoding/data modulations using the collected statistics.

Claims

1. A method for adjusting data modulation at a base station comprising:

receiving data at a transmitter for transmission;

formatting the received data into packets for transmission, each packet having a particular type of encoding/data modulation;

transmitting the packets;

monitoring a return channel for receipt of an acknowledgment for each packet that the packet has been received;

retransmitting a packet at the transmitter, if an acknowledgment for that packet has not been received;

collecting retransmission statistics; and

adjusting each particular type of encoding/data modulation using the collected retransmission statistics.

2. The method of claim 1 wherein the particular type of encoding/data modulation is forward error correction (FEC).

3. The method of claim 2 wherein the packets are transmitted using an orthogonal frequency division multiple access (OFDMA) air interface and the particular FEC encoding/data modulation adjusting is performed in addition to selective nulling of subchannels in an OFDMA set.

4. The method of claim 1 wherein the packets are transmitted using a single carrier having a frequency domain equalization (SC-FDE) air interface.

5. The method of claim 1 wherein the return channel is the fast feedback channel when the packets are transmitted using a code division multiple access (CDMA) air interface.

6. The method of claim 1 further comprising:

identifying a packet as having an unacceptable error rate responsive to receipt of a negative acknowledgment.

7. A method for adjusting data modulation at a base station, comprising:

formatting data into packets for transmission over a wireless air interface;

receiving packets of data over said air interface, each packet having a particular encoding/data modulation;

for each received packet, generating and transmitting a positive acknowledgment at the physical layer of said air interface when a received packet has an acceptable error rate.

8. The method of claim 7 wherein the positive acknowledgments are transmitted on the fast feedback channel when said air interface is a code division multiple access (CDMA).

9. The method of claim 7 further comprising transmitting a negative acknowledgment if that packet has an unacceptable error rate.