DYNAMIC SPECTRUM MANAGEMENT

• US 20120294168A1
• Filed: 11/01/2011
• Published: 11/22/2012
• Est. Priority Date: 11/01/2010
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Freda, Martino M., Demir, Alpaslan, Touag, Athmane, Chincholi, Amith V., Gauvreau, Jean-Louis, Leithead, Phillip L., Gopalan, Ramya, Gopalan, Sowmya
• Granted Patent: US 9,769,692 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 1/0067 with one or more circuit blocks in common for different bands
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/00 Local resource management
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

A wireless transmit/receive unit (WTRU) and a dynamic spectrum management (DSM) engine are described. The WTRU includes a transceiver, a radio frequency (RF) spectrum sensing unit and a processing unit. The transceiver transmits over a wireless link. The RF spectrum sensing unit measures information indicative of usage of a spectrum by other devices. The processing unit detects a change in performance of the wireless link, controls the transceiver to transmit a notification to a DSM engine indicating that the change in the performance of the wireless link was detected on a condition that the processing unit detects the change in performance of the wireless link, and receives a sensing task request for the WTRU to measure the information indicative of the usage of the spectrum by other devices based on the notification transmitted to the DSM engine indicating that the change in the performance of the wireless link was detected.

Claims

1. A wireless transmit/receive unit (WTRU) comprising:

a transceiver configured to communicate over a wireless link;

a radio frequency (RF) spectrum sensing unit configured to measure information indicative of usage of a spectrum by other devices; and

a processing unit configured to;

detect a change in performance of the wireless link,

on a condition that the processing unit detects the change in performance of the wireless link, control the transceiver to transmit a notification to a DSM engine indicating that the change in the performance of the wireless link was detected, and

receive a sensing task request for the WTRU to measure the information indicative of the usage of the spectrum by other devices based on the notification transmitted to the DSM engine indicating that the change in the performance of the wireless link was detected.

2. The WTRU of claim 1, wherein:

the RF spectrum sensing unit is further configured to measure the information indicative of the usage of the spectrum by the other devices responsive to the sensing task request, and

the transceiver is further configured to transmit results of the measuring to the DSM engine.

3. The WTRU of claim 1, further comprising receiving, from the DSM engine, an allocation of spectrum for communication that is not being used by the other devices.

4. The WTRU of claim 1, wherein the received sensing task request is included in a sensing configuration message that includes information for configuring the WTRU to perform the sensing task.

5. The WTRU of claim 4, wherein the sensing configuration message provides information for configuring the WTRU to perform a single sensing task or a plurality of sensing tasks to be carried out at periodic time intervals.

6. A method implemented in a dynamic spectrum management (DSM) engine, the method comprising:

allocating spectrum for use by a plurality of wireless transmit/receive units (WTRUs);

receiving a notification from one of the plurality of WTRUs indicating that the one of the plurality of WTRUs detected a change in performance of a wireless link corresponding to use of the spectrum by a primary user of the spectrum; and

in response to receiving the notification, transmitting a sensing task request to at least one of the plurality of WTRUs requesting the at least one of the plurality of WTRUs to measure information indicative of usage of the spectrum by other devices.

7. The method of claim 6, further comprising receiving sensing results from the plurality of WTRUs at a plurality of periodic intervals indicating whether information measured at each of the plurality of periodic intervals indicated that the spectrum was being used by the other devices at a time that the information was measured.

8. The method of claim 7, further comprising:

determining whether the sensing results provided by the plurality of WTRUs indicate that two or more of the plurality of WTRUs are correlated with one another; and

selecting an uncorrelated subset of the plurality of WTRUs to transmit the sensing task request to based on results of the determining.

9. The method of claim 6, further comprising:

receiving sensing results from each of the at least one of the plurality of WTRUs to which the sensing task request was sent providing a decision as to whether the measured information indicated that the spectrum is being used by the other devices; and

determining whether the other devices are using the spectrum based at least on the received sensing results and other information indicating a reliability of the received sensing results.

10. The method of claim 9, wherein the other information includes at least one of an estimated signal-to-noise ratio (SNR) and a number of samples used in a metric computation.

11. The method of claim 9, wherein the determining comprises:

attributing a weight to each of the received sensing results based on the information indicating the reliability of the received sensing results; and

combining the received sensing results into an overall metric using the weight assigned to each of the received sensing results.

12. The method of claim 8, wherein:

the sensing task request is transmitted to at least two of the plurality of WTRUs, and the method further comprises;

receiving I/Q data samples from the at least two of the plurality of WTRUs; and

determining whether the other devices are using the spectrum based on the received I/Q data samples.

13. The method of claim 12, wherein the determining whether the other devices are using the spectrum based on the received I/Q data comprises:

computing an average power spectral density (PSD) based on the received I/Q data samples; and

determining whether the other devices are using the spectrum based on the computed average PSD.

14. The method of claim 13, wherein the determining whether the other devices are using the spectrum based on the received I/Q data further comprises computing the average PSD over a configurable-length time window.

15. The method of claim 14, wherein a length of the configurable-length time window depends on at least one of a type of interferer to be detected by the WTRUs that receive the sensing task request, an amount of time required to detect the primary user of the spectrum, a mobility of the WTRUs that receive the sensing task request or a knowledge of a noise level on a channel.

16. The method of claim 12, wherein the determining whether the other devices are using the spectrum based on the received I/Q data samples comprises:

estimating autocorrelation properties of the received I/Q data samples;

calculating a decision metric based on the estimated autocorrelation properties;

determining whether the decision metric exceeds a decision threshold;

on a condition that the decision metric exceeds the decision threshold, determining that the other devices are using the spectrum; and

on a condition that the decision metric does not exceed the decision threshold, determining that the other devices are not using the spectrum.

17. The method of claim 16, wherein the calculating the decision metric is performed based on:

18. The method of claim 11, further comprising transmitting at least one new spectrum allocation to at least one of the plurality of WTRUs on a condition that it is determined that the other devices are using the spectrum that was previously allocated to the at least one of the plurality of WTRUs.

19. The method of claim 7, further comprising generating sensing objects including information for configuring hardware of the DSM engine to obtain the sensing results, wherein the hardware is configured differently depending on a content of the information included in each respective sensing object.