Method of optimising the rank of a mmse channel equaliser

A method of optimizing the rank of a Minimum Mean Squared Error (MMSE) channel equalizer in a wireless receiver, the method comprising the steps of:

• transmitting NACK and ACK messages by a wireless receiver;
• calculating the number of ACK and NACK messages transmitted;
• calculating an estimator of the throughput of the channel equalizer;
• wherein the estimator is dependent on a number of NACK messages transmitted by the receiver;
• establishing a first and second threshold for the percentage of NACK messages;
• adjusting the rank of the channel equalizer according to the throughput by increasing the rank if the percentage of NACK messages substantially exceeds the first threshold;
• and decreasing the rank if the percentage of NACK messages is substantially less than the second threshold;
• and
• repeating the above steps until the throughput of the channel equalizer substantially equals a desired value.

A method of determining the limit rank of a Minimum Mean Squared Error (MMSE) channel equalizer comprising the steps of:

• determining a first estimator of the throughput of the channel equalizer with a first valued rank of the channel equalizer;
• determining a second estimator the throughput of the channel equalizer with a second-valued rank of the channel equalizer;
• comparing the value of the second estimator with the value of the first estimator;
• determining a third estimator of the throughput of the channel equalizer, with a third-valued rank of the channel equalize being different than the second-valued rank, in the event that the value of the second estimator substantially differs from the value of the first estimator;
• comparing the value of the third estimator with the value of the second estimator;
• and repeating the operations of comparing values of successive second and third estimators until the values of sequential estimators are substantially equal.