Predictive data rate control in wireless transmitters

• US 6,707,862 B1
• Filed: 03/21/2000
• Issued: 03/16/2004
• Est. Priority Date: 03/21/2000
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Larsson, Torbjorn
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): WILLIAMS, LAWRENCE B
• Application Number:
  US09/531,997
• Time in Patent Office: 1,456 Days
• Field of Search: 375/262, 375/142, 375/326, 370/335-468, 370/449, 370/462, 455/69
• US Class Current: 375/326
• CPC Class Codes: H04L 25/0262 Arrangements for detecting the data rate of an incoming signal
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]

Abstract

A wireless transmitter includes a data rate controller operating to predictively determine a traffic channel data rate for a frame of data stream using a previous data rate, transmitted bit energy of a traffic channel, and a target data throughput. The data rate controller includes a selector, a bit energy computer, a predictor, an estimator, and a comparator.

Claims

1. A wireless transmitter, comprising:

a power transmitter, operating to transmit a data stream; and

a data rate controller operating to predictively determine a data rate for a frame of said data stream, using previously transmitted bit energy of a traffic channel, and a target data throughput;

wherein

said data rate controller includes a first selector to receive a target data throughput, said first selector operating to select a set of normalized thresholds based on said target data throughput;

said data rate controller further includes a bit energy computer to receive signal power level and a current data rate of a traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

said data rate controller further includes a predictor operating to predict bit energy distributed over a frame period using said transmitted bit energy;

said data rate controller further includes an estimator configured to compute a statistical distribution of average bit energy in said frame period using said predicted bit energy;

said estimator includes a weighted average calculator configured to compute average bit energy in said frame period by averaging said predicted bit energy; and

said averaging is performed by multiplying each predicted bit energy value with a specified weight, such that a sum of specified weights is equal to one.

2. The transmitter of claim 1, wherein said specified weights enable contributions from different predicted bit energy values to vary according to position of said values in said frame period.

3. The transmitter of claim 2, wherein said data rate controller further includes:

a running average computer adapted to compute a running average of a decimated bit energy; and

a differencing element operating to subtract said running average from said decimated bit energy.

4. A wireless transmitter, comprising:

a power transmitter, operating to transmit a data stream; and

a data rate controller operating to predictively determine a data rate for a frame of said data stream, using previously transmitted bit energy of a traffic channel, and a target data throughput;

wherein

said data rate controller includes a first selector to receive a target data throughput, said first selector operating to select a set of normalized thresholds based on said target data throughput;

said data rate controller further includes a bit energy computer to receive signal power level and a current data rate of a traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

said data rate controller further includes a predictor operating to predict bit energy distributed over a frame period using said transmitted bit energy;

said data rate controller further includes an estimator configured to compute a statistical distribution of average bit energy in said frame period using said predicted bit energy; and

said data rate controller further includes a second selector to determine a new data rate using said set of normalized thresholds, and said average bit energy and its statistical distribution.

5. A wireless transmitter, comprising:

a power transmitter, operating to transmit a data stream; and

a data rate controller operating to predictively determine a data rate for a frame of said data stream, using previously transmitted bit energy of a traffic channel, and a target data throughput;

wherein

said data rate controller includes a first selector to receive a target data throughput, said first selector operating to select a set of normalized thresholds based on said target data throughput;

said data rate controller further includes a bit energy computer to receive signal power level and a current data rate of a traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

said data rate controller further includes a predictor operating to predict bit energy distributed over a frame period using said transmitted bit energy; and

said data rate controller further includes a decimator operating to decimate said transmitted bit energy to a specified number of samples per frame before being sent to said predictor.

6. A wireless transmitter, comprising:

a first selector to receive a target data throughput, said first selector configured to select a set of normalized thresholds based on said target data throughput;

a bit energy computer to receive signal power of a traffic channel and a current data rate of said traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

a predictor operating to predict bit energy distributed over a frame using said transmitted bit energy;

an estimator configured to compute a statistical distribution of average bit energy in said frame period using said predicted bit energy;

a comparator to receive said normalized thresholds, and said average bit energy and its statistical distribution, said comparator determining a new data rate; and

a decimator operating to decimate said transmitted bit energy to a specified number of samples per frame before being sent to said predictor.

7. A wireless transmitter, comprising:

a first selector to receive a target data throughput, said first selector configured to select a set of normalized thresholds based on said target data throughput;

a bit energy computer to receive signal power of a traffic channel and a current data rate of said traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

a predictor operating to predict bit energy distributed over a frame using said transmitted bit energy;

an estimator configured to compute a statistical distribution of average bit energy in said frame period using said predicted bit energy;

a comparator to receive said normalized thresholds, and said average bit energy and its statistical distribution, said comparator determining a new data rate;

a running average computer adapted to compute a running average of a decimated bit energy; and

a differencing element operating to subtract said running average from said decimated bit energy.

8. A wireless transmitter, comprising:

a first selector to receive a target data throughput, said first selector configured to select a set of normalized thresholds based on said target data throughput;

a bit energy computer to receive signal power of a traffic channel and a current data rate of said traffic channel, said bit energy computer computing transmitted bit energy on said traffic channel;

a predictor operating to predict bit energy distributed over a frame using said transmitted bit energy;

an estimator configured to compute a statistical distribution of average bit energy in said frame period using said predicted bit energy; and

a comparator to receive said normalized thresholds, and said average bit energy and its statistical distribution, said comparator determining a new data rate;

wherein

said estimator includes a weighted average calculator configured to compute average bit energy in said frame period by averaging said predicted bit energy; and

said averaging is performed by multiplying each predicted bit energy value with a specified weight, such that a sum of specified weights is equal to one.

9. The transmitter of claim 8, wherein said specified weights enable contributions from different predicted bit energy values to vary according to position of said values in said frame period.