Weighted open loop power control transmitter
View Patent ↗A weighted open loop power control transmitter for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter's power level and to control the receiver's amplifier.
1. A User Equipment (UE) comprising:
a receiver configured to receive a signal that includes a transmission power level parameter, over a channel;
a power measurement device configured to measure a power level of the received signal;
an average pathloss estimation device configured to:
determine an instantaneous pathloss, L, that is a difference in value of the transmission power level parameter and the measured power level of the received signal;
output an average pathloss, L o , based upon the determined L;
a quality control device configured to:
determine a quality of the L o ;
apply a weighting factor α having a value between 0 and 1; and
output a transmit power level adjustment; and
a transmit power level determination device configured to determine a power level of a subsequent transmission signal from the UE based on the transmit power level adjustment, wherein the power level of the subsequent transmission is directly proportional to a sum of three factors: a first factor that is determined by multiplying the weighting factor α with the difference of L and L o ; a second factor that is L; and a third factor that is at least one other value received by the UE.
2. The UE of claim 1 , wherein the channel is a control channel.
3. The UE of claim 1 , wherein the subsequent transmission signal from the UE takes place over at least one time slot of a radio frame that is divided into a plurality of time slots.
4. The UE of claim 1 comprising an antenna configured to radiate the subsequent transmission signal.
5. The UE of claim 1 further comprising circuitry operatively coupled to the antenna to demodulate signals received by the antenna to produce a baseband signal.
6. The UE of claim 1 wherein the received signal and the subsequently transmitted signal are in a code division multiple access format.
7. The UE of claim 1 , wherein the weighting factor α is directly proportional to:
a ratio of A/B wherein A is equal to a first slot number on which information is transmitted and B is equal to the maximum allowed delay as represented in slot numbers.
8. The UE of claim 1 , wherein the weighting factor α is directly proportional to a ratio of a parameter (D) that is calculated as a difference between a time slot of a previous path loss estimate and a first time slot of data transmitted, and a maximum allowed delay (D max ) as represented in time slots.
9. The UE of claim 8 , wherein for D<D max , and D→D max , a difference between D and D max is small, and the average pathloss estimation device is configured to determine the pathloss as an instantaneous pathloss L.
10. The UE of claim 8 , wherein for D<D max , and a difference between D and D max is large, and the average pathloss estimation device is configured to determine the pathloss as a long term average pathloss L o .
11. The UE of claim 8 , wherein for D>D max , the weighting factor is set to zero (0), and the average pathloss estimation device is configured to determine the pathloss as a long term average pathloss L o .
12. The UE of claim 1 , wherein the received signal is separated by time.
13. The UE of claim 1 , wherein the received signal is separated by codes.
14. The UE of claim 1 , wherein the received signal is separated by time and codes.