Power control in a transmitter

• US 6,295,289 B1
• Filed: 08/13/1999
• Issued: 09/25/2001
• Est. Priority Date: 11/30/1998
• Status: Expired due to Fees

• Current Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Mandyam, Giridhar, Ionescu, Dumitru Mihai
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US09/374,573
• Time in Patent Office: 774 Days
• Field of Search: 370/342, 370/335-341, 370/465, 370/252, 370/320, 375/350, 375/150-156, 455/67.1, 455/69, 455/522, 455/450, 455/562, 455/550, 316/130, 341/146, 341/149, 341/222, 341/140
• US Class Current: 370/342
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/223 predicting future states of the transmission

Abstract

A receiving and transmitting apparatus includes receiver circuitry, sampling circuitry, downlink prediction circuitry, uplink prediction circuitry and gain calculation circuitry. A downlink signal is received at the receiver and sampled at the sampling circuitry. Downlink and uplink prediction circuitry is used to estimate transmission properties of the downlink and uplink signals, respectively. The downlink and uplink prediction circuitry estimates downlink and uplink signal properties based on a sequence of previous downlink signal samples and the uplink estimates, respectively, as well as corresponding sequences of tap coefficients. The gain calculation circuitry is coupled to the uplink predication circuitry and to a transmitter and can set a transmitter gain level based on the predicted uplink signal properties. A method of controlling power in a communication device includes storing a sequence of downlink signal samples, calculating a downlink signal estimate and an uplink signal estimate, and setting a transmission power level based on the estimated uplink signal. The downlink signal estimate is calculated using the sequence of downlink signal samples and a first sequence of tap coefficients. The uplink signal estimate is calculated using a sequence previous uplink signal estimates and a second sequence of tap coefficients.

Claims

1. A receiving and transmitting apparatus comprising:

receiver circuitry configured to receive a downlink signal;

sampling circuitry operatively coupled to the receiver circuitry and configured to sample the downlink signal;

downlink prediction circuitry coupled to the sampling circuitry to calculate an downlink signal estimate based on a sequence of previous downlink signal samples and a first sequence of tap coefficients;

uplink prediction circuitry to calculate an uplink signal estimate based on a stored sequence of previous uplink signal estimates and a second sequence of tap coefficients; and

gain calculation circuitry operatively coupled to the uplink prediction circuitry and a transmitter, the gain calculation circuitry being configured to determine a transmitter gain setting based on the uplink signal estimate.

2. A mobile unit for use in a code division multiple access cellular phone system comprising the apparatus of claim 1.

3. The apparatus of claim 1 wherein the second sequence of tap coefficients is derived from the first sequence of tap coefficients.

4. The mobile unit of claim 3, wherein the first and second sequences of tap coefficients are the same.

5. The apparatus of claim 1 wherein:

the downlink signal comprises a CDMA channel; and

each downlink signal sample in the sequence of previous downlink signal samples comprises a value determined at the sampling circuitry by sampling a received signal strength associated with the downlink CDMA channel.

6. The apparatus of claim 5 wherein the downlink CDMA channel comprises a pilot channel and sampling a received signal comprises sampling a signal envelope associated with the pilot channel.

7. The apparatus of claim 1 wherein the downlink signal comprises power control information and the apparatus further comprises circuitry to modify the stored sequence of previous uplink signal estimates based on the power control information.

8. The apparatus of claim 7 wherein the power control information comprises a delta modulated power control bit and wherein the apparatus further comprises:

circuitry to modify the transmitter gain setting by a threshold amount based on the power control bit; and

circuitry to predictively alter the threshold amount based on a previous threshold adjustment.

9. The apparatus of claim 7, wherein the circuitry to modify the stored sequence of previous uplink signal estimates comprises circuitry to backward-correct uplink signal estimates associated with the received power control information and circuitry to forward-correct other uplink signal estimates.

10. The apparatus of claim 1 further comprising tap coefficient update circuitry configured to modify the first sequence of tap coefficients as a function of the downlink signal estimate and a current downlink signal sample.

11. The apparatus of claim 10 wherein the downlink prediction circuitry, uplink prediction circuitry, and tap coefficient update circuitry comprise a software configurable processor.

12. A method of controlling power in a wireless communication device, the method comprising:

sampling a received downlink signal;

storing a sequence of downlink signal samples;

calculating a downlink signal estimate based on the sequence of downlink signal samples and a first sequence of tap coefficients;

calculating an uplink signal estimate based on a second sequence of tap coefficients and a sequence of previous uplink signal estimates; and

setting a transmission power level based on the uplink signal estimate.

13. The method of claim 12 wherein the first sequence of tap coefficients and the second sequence of tap coefficients are the same.

14. The method of claim 12 further comprising:

updating the first sequence of tap coefficients based on a current downlink signal sample and the downlink signal estimate.

15. The method of claim 14 wherein the second sequence of tap coefficients comprise the updated first sequence of tap coefficients.

16. The method of claim 12 further comprising receiving power control information from a remote station and updating the sequence of previous uplink signal estimates based on the received power control information.

17. The method of claim 16 wherein updating based on the received power control information comprises determining a subset of the sequence of previous uplink signal estimates corresponding to signal estimates associated with a transmitted signal monitored to determine the received power control information.

18. The method of claim 16 further comprising modifying the transmission power level based on the received power control information.

19. The method of claim 18 wherein the power control information comprises a delta modulated power control bit, modifying the transmission power level based on the received power control information comprises modifying by a threshold amount, and wherein the method further comprises modifying the threshold amount based on a sequence of previous threshold modifications.

20. The method of claim 12 wherein the downlink signal comprises a pilot channel and the downlink signal samples comprise a pilot channel envelope sample.

21. The method of claim 20 wherein the pilot channel envelope sample comprises a envelope signal strength sample.

22. The method of claim 12 wherein the wireless communications device is a time division multiple access cellular phone.