Apparatus and method for selecting modulation and filter roll-off to meet power and bandwidth requirements

• US 7,924,775 B2
• Filed: 01/29/2007
• Issued: 04/12/2011
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khan, Farooq, Tsai, Jiann-An
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): HAN, CLEMENCE S
• Application Number:
  US11/699,305
• Publication Number:
  US 20070218942A1
• Time in Patent Office: 1,534 Days
• Field of Search: None
• US Class Current: 370/328
• 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 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/2614 Peak power aspects
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0058 Allocation criteria

Abstract

A base station for use in a wireless network that communicates according to a multi-carrier protocol. The base station receives an uplink signal transmitted by a first subscriber station. The first subscriber station transmits using a configurable spectral shaping filter and a selectable modulation order. The base station determines a required bandwidth efficiency associated with the first subscriber station and, in response to the determination, selects a first modulation order and a first filter parameter to be used by the first subscriber station. Advantageously, the base station selects the first modulation order and the first filter parameter in order to maximize a power efficiency of the first subscriber station while maintaining the required bandwidth efficiency.

Claims

1. For use in a wireless network configured for communication with a plurality of subscriber stations according to a multi-carrier protocol, a base station operable to receive an uplink signal transmitted by a subscriber station, the subscriber station configured to transmit in the uplink using a configurable spectral shaping filter and using a plurality of selectable modulation orders, wherein the base station is configured to:

determine a required power efficiency associated with the subscriber station; and

select a modulation order and a filter parameter to be used by the subscriber station to transmit in the uplink, the modulation order and the filter parameter selected to maximize a bandwidth efficiency of the subscriber station while maintaining the required power efficiency.

2. The base station as set forth in claim 1, wherein the modulation order is one of binary phase shift keying (BPSK) modulation and quadrature phase shift keying (QPSK) modulation.

3. The base station as set forth in claim 1, wherein the filter parameter is used to configure the spectral shaping filter in the subscriber station.

4. The base station as set forth in claim 3, wherein the filter parameter comprises a root raised cosine (RRC) roll-off parameter.

5. The base station as set forth in claim 3, wherein the base station further selects a channel coding rate to be used by the subscriber station to transmit in the uplink.

6. The base station as set forth in claim 5, wherein the base station selects the modulation order, the filter parameter, and the channel coding rate in order to maximize a power efficiency of the subscriber station while maintaining a required bandwidth efficiency.

7. The base station as set forth in claim 5, wherein the base station selects the modulation order, the filter parameter, and the channel coding rate in order to provide an optimum tradeoff between power efficiency and bandwidth efficiency in the subscriber station.

8. For use in a wireless network configured for communication with a plurality of subscriber stations according to a multi-carrier protocol, a method of communicating in an uplink between a base station and a subscriber station, the subscriber station configured to transmit in the uplink using a configurable spectral shaping filter and using a plurality of selectable modulation orders, the method comprising the steps of:

determining a required power efficiency associated with the subscriber station; and

selecting a modulation order and a filter parameter to be used by the subscriber station to transmit in the uplink, the modulation order and the filter parameter selected to maximize a bandwidth efficiency of the subscriber station while maintaining the required power efficiency.

9. The method as set forth in claim 8, wherein the modulation order is one of binary phase shift keying (BPSK) modulation and quadrature phase shift keying (QPSK) modulation.

10. The method as set forth in claim 8, wherein the filter parameter is used to configure the spectral shaping filter in the subscriber station.

11. The method as set forth in claim 10, wherein the filter parameter comprises a root raised cosine (RRC) roll-off parameter.

12. The method as set forth in claim 10, further comprising the step of selecting a channel coding rate to be used by the subscriber station to transmit in the uplink.

13. The method as set forth in claim 12, wherein the steps of selecting the modulation order, selecting the filter parameter, and selecting the channel coding rate maximize a power efficiency of the subscriber station while maintaining a required bandwidth efficiency.

14. For use in a wireless network configured for communication with a plurality of subscriber stations according to a multi-carrier protocol, a base station operable to receive an uplink signal transmitted by a subscriber station, the subscriber station configured to transmit in the uplink using a configurable spectral shaping filter and using a plurality of selectable modulation orders, wherein the base station is configured to:

determine a required power efficiency associated with the subscriber station; and

select a modulation order, a filter parameter, and a data rate to be used by the subscriber station to transmit in the uplink, the modulation order and the filter parameter selected to maximize a bandwidth efficiency of the subscriber station while maintaining the required power efficiency.

15. The base station as set forth in claim 14, wherein the modulation order is one of binary phase shift keying (BPSK) modulation and quadrature phase shift keying (QPSK) modulation.

16. The base station as set forth in claim 14, wherein the filter parameter is used to configure the spectral shaping filter in the subscriber station.

17. The base station as set forth in claim 16, wherein the filter parameter comprises a root raised cosine (RRC) roll-off parameter.

18. The base station as set forth in claim 16, wherein the base station further selects a channel coding rate to be used by the subscriber station to transmit in the uplink.

19. The base station as set forth in claim 18, wherein the base station selects the modulation order, the filter parameter, and the channel coding rate in order to maximize a bandwidth efficiency of the subscriber station while maintaining a required power efficiency.

20. The base station as set forth in claim 18, wherein the base station selects the modulation order, the filter parameter, and the channel coding rate in order to provide an optimum tradeoff between power efficiency and bandwidth efficiency in the subscriber station.

21. For use in a wireless network configured for communication with a plurality of subscriber stations according to a multi-carrier protocol, a method of communicating in an uplink between a base station and a subscriber station, the subscriber station configured to transmit in the uplink using a configurable spectral shaping filter and using a plurality of selectable modulation orders, the method comprising the steps of:

determining a required power efficiency associated with the subscriber station; and

selecting a modulation order, a filter parameter, and a data rate to be used by the subscriber station to transmit in the uplink, the modulation order and the filter parameter selected to maximize a bandwidth efficiency of the subscriber station while maintaining the required power efficiency.

22. The method as set forth in claim 21, wherein the modulation order is one of binary phase shift keying (BPSK) modulation and quadrature phase shift keying (QPSK) modulation.

23. The method as set forth in claim 21, filter parameter is used to configure the spectral shaping filter in the subscriber station.

24. The method as set forth in claim 23, wherein the filter parameter comprises a root raised cosine (RRC) roll-off parameter.

25. The method as set forth in claim 23, further comprising the step of selecting a channel coding rate to be used by the subscriber station to transmit in the uplink.

26. The method as set forth in claim 25, wherein the steps of selecting the modulation order, selecting the filter parameter, and selecting the channel coding rate maximize a bandwidth efficiency of the subscriber station while maintaining a required power efficiency.