M-ary modulation for wireless systems

• US 20030110440A1
• Filed: 01/23/2003
• Published: 06/12/2003
• Est. Priority Date: 03/30/1998
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Gutierrez, Alberto Jr.
• Granted Patent: US 7,305,609 B2
• Time in Patent Office: Days
• US Class Current: 714/790
• 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 1/006 Trellis-coded modulation
• 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 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 5/1453 of modulation type

Abstract

Disclosed is a method of and apparatus for increasing the capacity of a wireless communication system. This is accomplished by having users that can support a higher than base modulation order be required to do so under predetermined conditions such as electrical distance from a base transceiver station (BTS) antenna to a user, the reception of data in a high speed burst (HSD) and the like. The same digital processor apparatus that may be used to provide a base order modulation scheme may be reprogrammed in a more complex fashion to provide signal processing at the higher modulation rate for any given user channel.

Claims

1. A method for increasing throughput in a CDMA network, comprising the steps of:

determining if a user can support communication at a higher modulation order than a base modulation order; and

communicating with the user at the higher modulation order.

2. The method of claim 1 wherein the base modulation order consists of QPSK modulation.

3. The method of claim 1 wherein the higher modulation order consists of 8-PSK.

4. The method of claim 1 wherein the higher modulation order comprises any M>

4 modulation order.

14. The method of claim 1, 6, 10, 11, or 12, wherein the higher modulation order is performed by the steps of:

n/(n+1) encoding an incoming signal to provide a second signal;

puncturing by removing 1 of each set of m bits of said second signal to produce a third signal;

in phase and quad phase mapping said third signal to provide fourth and fifth signals as outputs.

15. The method of claim 1, 6, 10, 11, or 12, wherein the higher modulation order is performed by the steps of:

n/(n+1) encoding an incoming signal to provide a second signal;

repeating the bits of said second signal to produce a third signal;

removing 1 of each set of m bits of said third signal to produce a fourth signal;

in phase and quad phase mapping said fourth signal to provide fifth and sixth signals as outputs.

16. The method of claim 1, 6, 10, 11, or 12, wherein the higher modulation order is performed by the steps of:

1/n encoding an incoming signal to provide a second signal;

removing 1 of each set of m bits of said second signal to produce a third signal;

in phase and quad phase mapping said third signal to provide fourth and fifth signals as outputs.

21. The method of claim 14 wherein n=2 and m=4.

22. The method of claim 15 wherein n=2 and m=4.

26. The method of claim 16 wherein n=3.

5. Cellular transmitter apparatus in a CDMA network, comprising:

means to communicate with a first modulation scheme;

means to communicate with a second modulation scheme; and

logic circuitry for selecting between the first and the second communication schemes.

6. A method for increasing throughput in a CDMA network, comprising the steps of:

normally using a base modulation order for all users communicating with a given base station;

determining, under predetermined conditions, if given users can support communication at a higher modulation order than said base modulation order; and

communicating with at least some of said given users the higher modulation order.

7. The method of claim 6 wherein the predetermined conditions comprises a given percentage of total radio and or code capacity is being used.

8. The method of claim 6 wherein the predetermined conditions comprises requiring HSD users to operate at a higher modulation order than the base modulation order.

9. The method of claim 6 wherein the predetermined conditions comprises requiring users electrically closest to a communicating antenna to operate at a higher modulation order than the base modulation order.

10. A method for increasing throughput in a wireless network, comprising the steps of:

establishing a base modulation order for all users communicating with a given base station; and

requiring users electrically closest to said given base station, who can support communication at a higher modulation order than said base modulation order, to use a higher modulation order than users electrically farther away from said given base station.

11. A method for increasing throughput in a CDMA network, comprising the steps of:

establishing a base modulation order for all users communicating with a given base station; and

requiring users wanting to send high speed data to do so at a higher modulation order than said base modulation order.

12. A method for increasing throughput in a wireless network, comprising the steps of:

determining if a user MS can support communication at a given higher modulation order; and

communicating with the MS using said given higher modulation order.

13. Cellular transmitter apparatus in a wireless network, comprising:

means to communicate with a first modulation scheme;

means to communicate with a second modulation scheme; and

logic circuitry for selecting between the first and the second communication schemes.

17. The cellular transmitter apparatus of claim 5 or 13, wherein the means to communicate with a first modulation scheme comprising:

a n/(n+1) encoder;

puncture means for removing bits for an output signal of said n/(n+1) encoder in accordance with a predetermined function; and

in phase and quad phase mapping means for mapping signals output by said puncture means.

18. The cellular transmitter apparatus of claim 5 or 13, wherein the means to communicate with a first modulation scheme comprising:

a n/(n+1) encoder;

bit repeating means for duplicating each bit output by said n/(n+1) encoder;

puncture means for removing bits for an output signal of said bit repeating means in accordance with a predetermined function; and

in phase and quad phase mapping apparatus for mapping signals output by said puncture means.

19. The cellular transmitter apparatus of claim 5 or 13, wherein the means to communicate with a first modulation scheme comprising:

a 1/n encoder;

puncture means for removing bits for an output signal of said 1/n encoder in accordance with a predetermined function; and

in phase and quad phase mapping means for mapping signals output by said puncture means.

20. The cellular transmitter apparatus of claim 5 or 13, wherein the means to communicate with a first modulation scheme comprising:

a n/(n+1) encoder;

puncture means for removing bits for an output signal of said n/(n+1) encoder in accordance with a predetermined function;

in phase and quad phase mapping means for mapping signals output by said puncture means;

symbol repetition means for duplicating the symbols output by said in phase and quad phase mapping means;

block interleaver means for reordering in phase and quad phase symbols output by said symbol repetition means; and

combining means for altering the output of said block interleaver means to a given Walsh code.

23. The method of claim 17 wherein n=2.

24. The method of claim 18 wherein n=2.

25. The method of claim 20 wherein n=2.

27. The method of claim 19 wherein n=3.