Apparatus and method for determining transmit signal parameters using real-time channel measurements

• US 20060148414A1
• Filed: 10/25/2005
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG), Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Tee, Lai King, Cleveland, Joseph R., Rensburg, Cornelius van
• Granted Patent: US 8,666,387 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]

Abstract

A method and wireless system that is able to adapt forward channel signal parameters to the different channel characteristics in each deployment environment. For example, the base station may update the waveform parameters based upon the real-time channel measurement feedback as received from the subscriber stations.

Claims

1. A method for determining transmit signal configuration parameters comprising:

receiving a signal in a subscriber station;

determining, from the signal, a channel impulse response value between a base station and the subscriber station;

estimating channel characteristics based on the channel impulse response value;

determining transmit signal configuration parameters based on the estimated channel characteristics; and

selecting at least one of the configuration parameters based on an estimation of channel impulse response.

2. The method of claim 1, further comprising sending the channel characteristics to a base station.

3. The method of claim 1, wherein the channel characteristics are selected from the group consisting of a delay spread, a power delay profile, and a frequency selectivity.

4. The method of claim 1, wherein the at least one configuration parameter is selected from the group consisting of sub-channelization, number and allocations of subcarriers and subchannels, subcarrier spacing, guard interval, guard time length, a number of pilot tones, a location of pilot tones, a coding method, and a quadrature amplitude modulation constellation size.

5. The method of claim 1, wherein the signal is received from a source selected from the group consisting of another subscriber station and a base station.

6. The method of claim 1, wherein the channel characteristics are estimated by comparing a channel output signal and a input measurement signal.

7. The method of claim 1, wherein the channel characteristics include a maximum channel delay spread determined according to at least one measurement of a path gain and delay of the received signal.

8. A subscriber station operable in a wireless network, comprising:

a transceiver; and

a processor capable of receiving a signal in a subscriber station,

determining, from the signal, a channel impulse response value between a base station and the subscriber station,

estimating channel characteristics based on the channel impulse response value.

9. The subscriber station of claim 8, wherein the subscriber station is further operable to determine transmit signal configuration parameters based on the estimated channel characteristics.

10. The subscriber station of claim 8, wherein the subscriber station is further operable to send the channel characteristics to a base station.

11. The subscriber station of claim 8, wherein the channel characteristics are selected from the group consisting of a delay spread, a power delay profile, and a frequency selectivity.

12. The subscriber station of claim 9, wherein the configuration parameters are selected from the group consisting of sub-channelization, number and allocations of subcarriers and subchannels, subcarrier spacing, guard interval, a guard time length, a number of pilot tones, a location of pilot tones, a coding method, and a quadrature amplitude modulation constellation size.

13. The subscriber station of claim 8, wherein the signal is received from a source selected from the group consisting of another subscriber station and a base station.

14. The subscriber station of claim 8, wherein the channel characteristics are estimated by comparing a channel output signal and a input measurement signal.

15. The subscriber station of claim 8, wherein the channel characteristics include a maximum channel delay spread determined according to at least one measurement of a path gain and delay of the received signal.

16. A base station operable in a wireless network, comprising:

a transceiver configured to transmit a first signal to a plurality of subscriber stations; and

a controller capable of analyzing at least one of channel characteristics and configuration parameters received from at least one subscriber station, and

modifying the transmission of the first signal in response to at least one of a received configuration parameter and a received channel characteristics.

17. The base station of claim 16, wherein the configuration parameters are selected from the group consisting of sub-channelization, number and allocations of subcarriers and subchannels, subcarrier spacing, guard interval, a guard time length, a number of pilot tones, a location of pilot tones, a coding method, and a quadrature amplitude modulation constellation size.

18. The base station of claim 16, wherein the configuration parameters are received from a plurality of subscriber stations.

19. The base station of claim 16, wherein the base station modifies the transmission of the first signal in a real-time response to receiving the configuration parameters.

20. A base station operable in a wireless network, comprising:

a transceiver configured to transmit a first signal to a plurality of subscriber stations and to determine a channel impulse response value between a base station and at least one subscriber station; and

a controller capable of estimating channel characteristics based on the channel impulse response value,

determining transmit signal configuration parameters based on the estimated channel characteristics, and modifying the transmission of the first signal in response to the transmit signal configuration parameters.

21. The base station of claim 20, wherein the transmit signal configuration parameters are selected from the group consisting of sub-channelization, number and allocations of subcarriers and subchannels, subcarrier spacing, guard interval, a guard time length, a number of pilot tones, a location of pilot tones, a coding method, and a quadrature amplitude modulation constellation size.

22. The base station of claim 20, wherein the base station modifies the transmission of the first signal in a real-time response to estimating the channel characteristics.