Coding/modulation scheme selection technique

• US 6,330,288 B1
• Filed: 01/28/1999
• Issued: 12/11/2001
• Est. Priority Date: 01/28/1999
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Schefczik, Hans-Peter, Nanda, Sanjiv, Budka, Kenneth Carl
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): JIANG, LENNY R
• Application Number:
  US09/238,561
• Time in Patent Office: 1,048 Days
• Field of Search: 375/295, 375/296, 375/135, 375/146, 332/123, 332/159, 714/786, 714/790, 714/704, 455/91, 455/102
• US Class Current: 375/296
• 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 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement

Abstract

In a wireless data network, such as a General Packet Radio Service (GPRS) network, a transmitter uses one of k coding/modulation schemes for transmitting data. The transmitter initially selects a coding/modulation scheme, C, as a function of carrier-to-interference ratio (C/I) measurements. The transmitter then calculates the number of blocks, B, required to transmit a number of data packets, D, using the coding/modulation scheme C. In addition, the transmitter calculates the number of blocks required to transmit the number of data packets, D, for each coding/modulation scheme that is stronger than the selected coding/modulation scheme C. The transmitter finally selects that coding/modulation scheme that results in transmitting the number of data packets D in B blocks using the strongest coding/modulation scheme. As a result, each block is transmitted using the strongest coding/modulation scheme available.

Claims

1. A method for selecting one of k coding/modulation schemes in a transmitter, the method comprising the steps of:

(a) measuring a channel quality metric (CQM);

(b) selecting one of the k coding/modulation schemes as a function of the measured CQM;

(c) calculating a number of blocks, B, required to transmit a given amount of data, D, using the selected coding/modulation scheme; and

(d) selecting the strongest coding/modulation scheme capable of transmitting as packets, the given amount of data packets D in B blocks.

2. The method of claim 1 wherein step (d) includes the step of calculating a respective number of blocks required to transmit the data D for each coding/modulation scheme that offers higher protection than the selected coding/modulation scheme.

3. The method of claim 1 wherein the transmitter is a wireless transmitter.

4. A transmitter comprising:

receiving circuitry for use in measuring a channel quality metric (CQM);

a processor for selecting one of k coding/modulation schemes for use in transmission of an amount of data, D;

wherein the processor (a) selects one of the k coding/modulation schemes as a function of the measured CQM, (b) calculates a number of blocks, B, required to transmit the data, D, using the selected coding/modulation scheme, and (c) selecting the strongest coding/modulation scheme capable of transmitting as packets, the given amount of data packets D in B blocks.

5. The apparatus of claim 4, wherein the transmitter is a wireless transmitter.