Patent ID: 7180956

Claim:
A method of applying overlaid perturbation vectors for gradient feedback transmit antenna array adaptation in a communication system, wherein the communication system includes a transmitter and a receiver, and wherein the transmitter includes a plurality of antennae, comprising the steps of: a) overlaying at least one weight vector perturbation vector; b) measuring signals transmitted in accordance with multiple weight vector perturbation vectors during a measurement interval, wherein the measurement interval has a greater duration than a feedback interval; c) generating a feedback based on the measurements of step (b); d) determining a new weight vector perturbation vector based on the feedback generated in the step (c); and e) returning to the step (a); wherein, at a time i, an even weight vector w even (i), an odd weight vector w odd (i), and a data weight vector w(i), are represented by the following equations in which w base (i) at least approximates a preceding weight vector, β comprises an algorithm parameter, I comprises a number of time periods, and v(k) comprises a perturbation vector: ⁢ i ) ⁢ ⁢ w even ⁡ ( i ) = w base ⁢ ⁡ ( i ) + β ⁢  w base ⁢ ⁡ ( i )  · ∑ k = i - I + 1 i ⁢ ⁢ v ⁡ ( k )  w base ⁢ ⁡ ( i ) + β ⁢  w base ⁢ ⁡ ( i )  · ∑ k = i - I + 1 i ⁢ ⁢ v ⁡ ( k )  ; ⁢ ⁢ ii ) ⁢ ⁢ w odd ⁡ ( i ) = w base ⁢ ⁡ ( i ) - β ⁢  w base ⁢ ⁡ ( i )  · ∑ k = i - I + 1 i ⁢ ⁢ v ⁡ ( k )  w base ⁢ ⁡ ( i ) - β ⁢  w base ⁢ ⁡ ( i )  · ∑ k = i - I + 1 i ⁢ ⁢ v ⁡ ( k )  ; ⁢ and ⁢ ⁢ ⁢ ⁢ iii ) ⁢ ⁢ w ⁡ ( i ) = w even ⁡ ( i ) + w odd ⁡ ( i ) 2 .