Granted Patent B2

US 8,750,236 · App. 13/618,895 · Granted Jun 10, 2014

Abstract

Claims (40)

1. A mobile subscriber device, comprising:

a radio frequency front end processor;

a baseband processor that exchanges signals with the radio frequency front end processor, wherein the baseband processor includes:

a modulator/demodulator for modulating and demodulating transmissions;

a mode selector; and

a qualified downlink transmission identifier, wherein the mode selector and the qualified downlink transmission identifier are configured to:

determine a predictive window;

determine a first estimate of a transmission mode based on averaged channel quality measurements, which are dependent upon a size of the predictive window;

calculate a margin based on reception of a qualifying downlink transmission;

decrease the margin upon an inference that the qualifying downlink transmission is correctly received and a determination that a burst that is scheduled by a base station includes a higher or equal spectral efficiency than a spectral efficiency of a set of N most recently selected transmission modes, where N is a positive integer greater than 1; and

select the transmission mode between the mobile subscriber device and the base station by updating the first estimate with the margin.

2. The device of claim 1 , wherein determining the predictive window comprises selecting the predictive window based on an estimation of a frequency of variations in a downlink channel between the mobile subscriber device and the base station.

3. The device of claim 1 , wherein determining the predictive window comprises monitoring how frequently the base station requests feedback of a downlink channel between the mobile subscriber device and the base station.

4. The device of claim 1 , wherein determining the predictive window includes a number of transmission frames that depend on a mobility of the mobile subscriber device.

5. The device of claim 1 , wherein determining the predictive window comprises the base station determining the predictive window.

6. The device of claim 1 , wherein determining the predictive window comprises the mobile subscriber device determining the predictive window.

7. The device of claim 1 , wherein a number of channel quality measurements that are averaged is dependent upon the size of the predictive window.

8. The device of claim 1 , wherein determining a first estimate of the transmission mode includes accessing a look up table based on the averaged channel quality measurements.

9. The device of claim 8 , wherein the look up table is selected based on one or more of an expected wireless environment, a data type being communicated, or a desired quality of service for transmission data.

10. The device of claim 1 , wherein the qualifying downlink transmission comprises a burst.

11. The device of claim 1 , wherein a desired quality of service (QoS) is used for determination of whether a downlink transmission is designated as a qualified downlink transmission.

12. The device of claim 11 , wherein determination of whether a downlink transmission is designated as a qualified downlink transmission comprises matching a connection identifier of the downlink transmission with a connection identifier of a particular QoS profile which a user of the mobile subscriber device is expecting.

13. The device of claim 12 , wherein the desired QoS is used for determination of the margin.

14. The device of claim 1 , wherein the qualifying downlink transmission includes forward error correction (FEC) blocks that include a cyclic redundancy check (CRC).

15. The device of claim 14 , wherein the qualifying downlink transmission can be inferred to be correctly received if the cyclic redundancy check (CRC) is successfully received or a confidence level of an output of a block FEC decoder is above a threshold.

16. The device of claim 1 , wherein the margin decays over time if no qualifying downlink transmissions are scheduled by the base station.

17. A mobile subscriber device, comprising:

a radio frequency front end processor;

a baseband processor that exchanges signals with the radio frequency front end processor, wherein the baseband processor includes:

a modulator/demodulator for modulating and demodulating transmissions;

a mode selector; and

a qualified downlink transmission identifier, wherein the mode selector and the qualified downlink transmission identifier are configured to:

determine a predictive window;

determine a first estimate of a transmission mode by accessing a look up table based on averaged channel quality measurements, which are dependent upon a size of the predictive window;

calculate a margin based on reception of a qualifying downlink transmission;

increase the margin upon an inference that the qualifying downlink transmission is incorrectly received and a determination that a burst that is scheduled by a base station includes a lower or equal spectral efficiency than a spectral efficiency of a set of N most recently selected transmission modes, where N is a positive integer greater than 1; and

select the transmission mode between the mobile subscriber device and the base station by updating the first estimate with the margin.

18. The device of claim 17 , wherein determining a predictive window comprises selecting the predictive window based on an estimation of a frequency of variations in a downlink channel between the mobile subscriber device and the base station.

19. The device of claim 17 , wherein determining the predictive window comprises monitoring how frequently the base station requests feedback of a downlink channel between the mobile subscriber device and the base station.

20. The device of claim 17 , wherein determining the predictive window includes a number of transmission frames that depend on a mobility of the mobile subscriber device.

Assignments (8)