Transmitter and receiver tracking techniques for user devices in a MIMO network

Abstract

A technique includes (i) receiving a first pilot signal from a base station via a receiver of a client device, or (ii) transmitting a second pilot signal from the client device to the base station via a transmitter of the client device. First time differences and signal quality values for N samples of N respective packets in the first pilot signal are determined. Second time differences and signal quality values are received via the receiver. The second time differences and signal quality values are generated for M samples of M respective packets in the second pilot signal. An offset value is determined based on (i) the first time differences and signal quality values, or (ii) the second time differences and signal quality values. Activation or deactivation times of the receiver or the transmitter or transmission times of the transmitter are adjusted based on the offset value.

What is claimed is: 
     
       1. A computer-implemented method of tuning at least one of a receiver and a transmitter of a client device, the method comprising:
 at least one of (i) receiving a first pilot signal from a base station via the receiver of the client device, and (ii) transmitting a second pilot signal from the client device to the base station via the transmitter of the client device; 
 at least one of:
 (i) determining, via one of a physical layer device (PHY) and a medium access controller (MAC) of the client device, first time differences and first signal quality values for N samples of N respective packets in the first pilot signal, where N is an integer greater than 1; and 
 (ii) receiving second time differences and second signal quality values from the base station via the receiver of the client device, wherein the second time differences and second signal quality values are generated for M samples of M respective packets in the second pilot signal at the base station, where M is an integer greater than 1; 
 
 comparing each of the first time differences or the second time differences to a preselected amount of time in one of the PHY and the MAC; 
 for each of the first time differences or the second time differences that is less than or equal to the preselected amount of time, generating a complex number based on (i) the corresponding first time difference or second time difference, and (ii) one of the first signal quality values and second signal quality values; 
 weighting the complex numbers with respective ones of the first signal quality values or second signal quality values; 
 determining, via one of the PHY and the MAC, an offset value based on the weighted complex numbers; and 
 adjusting, via the PHY and based on the offset value, at least one of:
 (i) an activation time or a deactivation time of the receiver of the client device; and 
 (ii) a transmission time, an activation time, or a deactivation time of the transmitter of the client device. 
 
 
     
     
       2. A computer-implemented method of tuning a receiver of a client device, the method comprising:
 receiving a pilot signal from a base station via the receiver of the client device; 
 sampling the pilot signal to determine receive times for N samples via the receiver of N respective packets in the pilot signal, where N is an integer greater than 1; 
 determining, via one of a PHY and a MAC of the client device, time differences between the receive times and respective predetermined times of the client device for each of the N samples; 
 comparing each of the time differences to a preselected amount of time in one of the PHY and the MAC; 
 determining signal quality values for each of the N samples using one of the PHY and the MAC based on the comparisons of the time differences, wherein the signal quality values are determined signal strengths of the pilot signal; 
 for each of the N samples, when the one of the time differences is less than or equal to a preselected amount of time, generating a complex number based on (i) one of the time differences, and (ii) one of the signal quality values; 
 weighting the complex numbers with respective ones of the signal quality values; 
 summing the complex numbers to generate a sum; 
 determining an offset value based on an argument of the sum; and 
 adjusting, via the PHY and based on the offset value, an activation time or a deactivation time of the receiver of the client device. 
 
     
     
       3. The computer-implemented method of  claim 2 , further comprising:
 receiving a static symbol from the base station; and determining the offset value based on the static symbol. 
 
     
     
       4. The computer-implemented method of  claim 2 , further comprising receiving a compound signal from the base station, wherein:
 the compound signal includes a data signal and the pilot signal, wherein the data signal includes user data, and wherein the pilot signal is transmitted at a carrier frequency and modulated with respect to the data signal; and the compound signal is transmitted in television whitespace and is a time division multiplexed signal. 
 
     
     
       5. The computer-implemented method of  claim 4 , further comprising determining the offset value based on parameters, wherein:
 the parameters are determined by the base station; and the compound signal includes fields identifying the parameters. 
 
     
     
       6. The computer-implemented method of  claim 2 , further comprising:
 transmitting a request for additional symbols or allocated time slots from the client device to the base station; and determining the offset value based on parameters associated with samples of signals transmitted at times of the additional symbols or allocated time slots. 
 
     
     
       7. A computer-implemented method of tuning a transmitter of a client device, the method comprising: transmitting a pilot signal from the client device to a base station via the transmitter of the client device;
 generating time differences for M samples of M respective packets in the pilot signal where M is an integer greater than 1, based on arrival times of the M packets in the pilot signal at the base station and corresponding predetermined allocation times of the client device; 
 comparing each of the time differences to a preselected amount of time in one of a PHY and a MAC of a client device; 
 determining signal quality values based on the comparisons of the time differences, wherein the signal quality values are determined signal strengths of the pilot signal; 
 for each of the M samples, when the one of the time differences is less than or equal to a preselected amount of time, generating a complex number based on (i) one of the time differences, and (ii) one of the signal quality values; 
 weighting the complex numbers with respective ones of the signal quality values; 
 summing the complex numbers to generate a sum; 
 determining an offset value based on an argument of the sum; and 
 adjusting, via the PHY and based on the offset value, at least one of a transmission time, an activation time, or a deactivation time of the transmitter of the client device. 
 
     
     
       8. The computer-implemented method of  claim 7 , further comprising: receiving a static symbol from the base station; and determining the offset value based on the static symbol. 
     
     
       9. The computer-implemented method of  claim 7 , further comprising
 receiving a compound signal from the base station, wherein: the compound signal includes a data signal and the pilot signal, wherein the data signal includes user data, and wherein the pilot signal is transmitted at a carrier frequency and modulated with respect to the data signal; and the compound signal is transmitted in television whitespace and is a time division multiplexed signal. 
 
     
     
       10. The computer-implemented method of  claim 9 , further comprising determining the offset value based on parameters, wherein: the parameters are determined by the base station; and the compound signal includes fields identifying the parameters. 
     
     
       11. The computer-implemented method of  claim 7 , further comprising: transmitting a request for additional symbols or allocated time slots from the client device to the base station; and determining the offset value based on parameters associated with samples of signals transmitted at times of the additional symbols or allocated time slots.