A window-margin-like procedure for evaluating PRML channel performance

A procedure for rapidly evaluating the error rate performance of PRML channels is derived. The procedure, Sequenced Amplitude Margin (SAM), is a direct analogy to window margin techniques that are used for evaluating peak detection channels. SAM is computed from amplitude sampling errors, while window margin is a function of peak timing errors. Examples of the use of SAM to optimize filters, evaluate off-track performance, and compare PR4 with E/sup 2/PR4 systems are described.<>