	US 7,499,486 B2
	Data transmission rate adaptation in a wireless communication system
Jan Boer, Odijk (Netherlands); Bas Driesen, Dongen (Netherlands); Ra'anan Gil, Nieuwegein (Netherlands); and Kai Roland Kriedte, Woerden (Netherlands)
Assigned to Agere Systems Inc., Allentown, Pa. (US)
Filed on Nov. 27, 2002, as Appl. No. 10/305,554.
Prior Publication US 2004/0101035 A1, May 27, 2004
Int. Cl. H04L 1/00 (2006.01); H04J 3/16 (2006.01)

U.S. Cl. 375—219 [375/225; 375/227; 375/295; 375/296; 370/252; 370/465]

12 Claims

1. In a wireless system comprising at least one transceiver configurable for communication over a wireless communication channel, the transceiver comprising a transmitter and a receiver, a method for controlling a data transmission rate of the at least one transceiver, the method comprising the steps of:

determining a signal quality characteristic corresponding to a signal received at the receiver by measuring a difference between one or more reference constellation points and one or more received constellation points, the signal quality characteristic representing an estimation of signal degradation through the wireless communication channel; and

modifying a data transmission rate of the transmitter based, at least in part, on the signal quality characteristic;

wherein the step of determining the signal quality characteristic comprises measuring a difference between one or more reference constellation points and one or more received constellation points for at least one of data samples and control samples corresponding to the received signal;

wherein the step of measuring the difference between one or more reference constellation points and one or more received constellation points comprises the steps of:

converting the received signal into at least a real component and an imaginary component;

combining the imaginary component of the received signal with an absolute value of the real component to generate a complex signal;

measuring a difference between the complex signal and an amplitude reference signal for a corresponding subcarrier of the received signal; and

determining a magnitude of the difference between the complex signal and the amplitude reference signal, the magnitude representing the measured difference between the one or more reference constellation points and the one or more received constellation points.