Data signal demodulation in a communication system
AssigneeTexas Instruments Incorporated
InventorsAris Papasakellariou, Timothy Schmidl, Anand Dabak
Life of this patent
Estimating the term…
Abstract
A method described evaluates the pilot-to-data power ratio based on the values of the demodulated data at the output of a receiver such as a conventional maximal ratio combiner or an equalizer receiver. Since the data are not scaled to their particular decision grid, their distribution and statistics deviate from the ones defined by the known decision grid. Measuring these deviations of the statistics, the pilot-to-data power ratio and the appropriate demodulated data scaling can be accurately determined. Subsequent data processing may then commence.
Claims21
In a communication system that transmits at least one data signal, a communication device having an output, the communication device having a receiver and demodulating the at least one data signal, the communication device performing the steps of:
- (a) taking the absolute values of the at least one data signal at the output of the receiver;
- (b) accumulating the absolute values;
- (c) using the accumulated absolute values and a predetermined number to obtain a scaling factor;
- (d) using the scaling factor to scale the at least one data signal at the output of the receiver and obtain at least one scaled result;
- and
- (e) using the at least one scaled result from step (d) to perform the demodulation of the at least one data signal at the output of the receiver.
In a communication system with transmission of at least one data signal and a pilot signal, a communication device having a receiver and operable in the communication system for determining the power ratio between the data and pilot signals, the communication device performing the steps of:
- (a) taking absolute values of the at least one data signal at the output of the receiver;
- (b) accumulating the absolute values to obtain a first value;
- (c) using the first value with a first predetermined number to obtain a first scaling factor;
- (d) accumulating the pilot signal values at the output of the receiver to obtain a second value
- (e) using the second value with a second predetermined number to obtain a second scaling factor
- (f) using the first scaling factor in step (c) and the second scaling factor in step (e) to obtain an estimate for the power ratio of the at least one data signal and the pilot signal;
A communication device having a receiver and operable in a communication system that transmits at least one data signal, the communication device performing the steps of:
- (a) computing orders of statistics for at least one data signal at the output of the receiver;
- (b) comparing the computed orders of the statistics to corresponding predefined values;
- and
- (c) using the results of the comparison in step (b) to determine a scaling factor for the at least one data signal at the output of the receiver.
Dependencies are inferred from the claim text.