Patent ID: 8305942

Claim:
A Multiple-Input, Multiple Output (MIMO) wireless communication method comprising: transmitting precoded MIMO signals at least from a transmitter to a receiver; estimating the Eigen coherence bandwidth of a MIMO channel on the basis of a root mean square (r.m.s.) delay spread (T rms ); and adjusting one or more precoding parameters used in said transmitter on the basis of said Eigen coherence bandwidth, prior to repeating the transmitting, wherein the method is a closed-loop Frequency Division Duplex (FDD) wireless communication method in which the estimating is performed in the receiver, and the receiver provides feedback signals to the transmitter including a value (K) indicative of the Eigen coherence bandwidth, the transmitter transmitting the MIMO signals on a plurality (L) of frequency fingers; the receiver detecting a channel gain and delay time for each of the L frequency fingers in a Single-Input Single Output (SISO) channel, and for each of a plurality of such SISO channels derived from the MIMO signals; and said estimating includes converting the channel response into the time domain to yield a channel gain and a delay time for each SISO channel, and calculating the average r.m.s, delay spread of the SISO channels from the channel gains and the delay times.