Claims
- 1. A method of wireless communication wherein a signal timing deviation is determined and used to adjust a User Equipment (UE) transmission comprising:
setting a threshold for measuring the timing deviation based on the energy level of the UE signal and evaluating signal samples which exceed the threshold to determine timing deviation.
- 2. The invention according to claim 1 wherein the UE transmits signals in bursts designated for specific timeslots of system time frames further comprising computing the energy level of at least a portion of a received UE burst to determine the energy level used to set the threshold.
- 3. The invention according to claim 2 wherein the UE bursts include a midamble and the energy level of the midamble of a received UE burst is computed to determine the energy level used to set the threshold.
- 4. The invention according to claim 3 further comprising defining a reception window based on the type of UE burst received and a timeslot designated for reception, sampling UE burst midambles received within the defined window and performing channel estimation to determine midamble channel impulse responses wherein the energy level of the midamble of a received UE burst is computed based on a selected combination of elements of the midamble channel impulse responses and the timing deviation is determined based on a relationship of midamble channel impulse responses to the threshold.
- 5. The invention according to claim 4 further wherein the UE bursts have a predefined chip rate, the sampling of UE burst midambles is at twice the chip rate, the channel estimation is performed on even and odd samples of received midambles to produce oversampled midamble channel impulse responses, the energy level of the midamble of a received UE burst is computed based on a summation of the squares of non-noise oversampled midamble channel impulse response elements and the timing deviation is determined based on oversampled midamble channel impulse responses whose square exceeds the threshold.
- 6. The invention according to claim 5 wherein the threshold is set at a value equal to the computed the energy level multiplied by a constant which is determined by conducting simulations.
- 7. The invention according to claim 4 wherein the UE bursts have a predefined chip rate and a midamble sequence of one of K shifts of a predetermined sequence, a number k, which is ≦K, of UE bursts are received within the same designated timeslot, each having a different midamble shift, the sampling of the k received UE burst midambles is at twice the chip rate, the channel estimation is performed using the Steiner algorithm on even and odd samples of received midambles to produce oversampled midamble channel impulse responses for each of the k received midambles, the energy level of the midamble of at least one of the k received UE bursts is computed based on a summation of the squares of the non-noise oversampled midamble channel impulse responses for that burst and the timing deviation is determined based on the oversampled midamble channel impulse responses for that burst whose squares exceeds the threshold.
- 8. The invention according to claim 7 wherein the threshold is set at a value equal to the computed the energy level multiplied by a constant which is in the range of 0.01 and 0.05.
- 9. The invention according to claim 7 further comprising using the determined timing deviation to generate a timing advance signal and transmitting the generated timing advance signal to the UE which transmitted the burst for which the timing deviation was determined.
- 10. The invention according to claim 9 further comprising receiving the generated timing advance signal by the UE which transmitted the burst for which the timing deviation was determined and using the timing advance signal to adjust transmission timing of that UE.
- 11. A wireless communication system for communicating with multiple User Equipments (UEs) wherein a signal timing deviation is determined by the system and used to adjust a User Equipment (UE) transmission comprising a receiver for receiving UE transmissions and associated processing circuitry which processes received UE signals and sets a threshold for measuring timing deviation of a received UE signal based on the energy level of the received UE signal and compares signal samples which exceed the threshold to determine timing deviation.
- 12. The invention according to claim 11 wherein the UE transmits signals in bursts designated for specific timeslots of system time frames and the processing circuitry computes the energy level of at least a portion of a received UE burst to determine the energy level used to set the threshold.
- 13. The invention according to claim 12 wherein the UE bursts include a midamble and the processing circuitry computes the energy level of the midamble of a received UE burst to determine the energy level used to set the threshold.
- 14. The invention according to claim 13 wherein the processing circuitry is configured to define a reception window based on the type of UE burst received and a timeslot designated for reception, sample UE burst midambles received within the defined window, perform channel estimation to determine midamble channel impulse responses, compute the energy level of the midamble of a received UE burst based on a selected combination of the midamble channel impulse responses and determine timing deviation based a relationship of midamble channel impulse responses to the threshold.
- 15. The invention according to claim 14 further wherein the UE bursts have a predefined chip rate and the processing circuitry is configured to sample UE burst midambles at twice the chip rate, perform channel estimation on even and odd samples of received midambles to produce oversampled midamble channel impulse responses, compute the energy level of the midamble of a received UE burst based on a summation of the squares of non-noise oversampled midamble channel impulse responses and determine timing deviation based on oversampled midamble channel impulse responses whose square exceeds the threshold.
- 16. The invention according to claim 15 wherein the processing circuitry is configured to set the threshold at a value equal to the computed the energy level multiplied by a constant.
- 17. The invention according to claim 14 wherein the UE bursts have a predefined chip rate and a midamble sequence of one of K shifts of a predetermined sequence, a number k, which is ≦K, of UE bursts are received within the same designated timeslot, each having a different midamble shift, and the processing circuitry is configured to sample the k received UE burst midambles at twice the chip rate, perform channel estimation using the Steiner algorithm on even and odd samples of received midambles to produce oversampled midamble channel impulse responses for each of the k received midambles, compute the energy level of the midamble of at least one of the k received UE bursts based on a summation of the squares of the oversampled midamble channel impulse responses for that burst and determine timing deviation based on the oversampled midamble channel impulse responses for that burst whose squares exceeds the threshold.
- 18. The invention according to claim 17 wherein the processing circuitry is configured to set the threshold at a value equal to the computed the energy level multiplied by a constant which is in the range of 0.01 and 0.05.
- 19. The invention according to claim 17 wherein the processing circuitry is configured to use the determined timing deviation to generate a timing advance signal and further comprising a transmitter which transmits the generated timing advance signal to the UE which transmitted the burst for which the timing deviation was determined.
- 20. The invention according to claim 19 wherein the processing circuitry is embodied in a Radio Network Controller (RNC) and the receive and transmitter are embodied in a Node B of a Third Generation Partnership Project system.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Serial No. 60/357,033, filed Feb. 14, 2002, which is incorporated by reference herein as if fully set forth.
Provisional Applications (1)
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Number |
Date |
Country |
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60357033 |
Feb 2002 |
US |