A transmitter may be operable to generate a sequence of symbols which may comprise information symbols and one or more pilot symbols. The transmitter may transmit the information symbols at a first power and transmit the one or more pilot symbols at a second power. In instances when a particular performance indicator is below a determined threshold, the first power may be set to a first value and the second power may be set to zero value. In instances when the particular performance indicator is above the determined threshold, the first power may be set to a second value and the second power may be set to a non-zero value. A value of the first power and a value of the second power may be based on an applicable average power limit determined by a communications standard with which the transmitter is to comply.

Quasi-reduced state trellis equalization techniques achieve low-latency inter-symbol interference (ISI) equalization by selecting a subset of accumulated path metrics (APMs) for a leading symbol to propagate over a trellis to candidate states of a trailing symbol. This simplifies the computation of APMs for candidate states of the trailing symbol. Thereafter, APMs for candidate states of the trailing symbol are computed based on the subset of APMs for the leading symbol that were propagated over the trellis. Propagating fewer than all APMs for the leading symbol to the trailing symbol reduces the complexity of APM computation at the trailing symbol.

Systems and methods are provided for detecting bit errors and further processing bit error information. A method, according to one implementation, includes the step of receiving a binary test sequence pattern generated by a pattern generator at an input to a digital communications system under test, wherein the binary test sequence pattern includes a plurality of sub-patterns. The method also includes the step of receiving an output binary sequence from an output of the digital communications system. Also, the method includes comparing the binary test sequence pattern with the output binary sequence to detect bit errors. Based on correlation characteristics between the bit errors and each of the sub-patterns, the method also includes the step of determining whether the bit errors are caused by random factors or are caused by deterministic factors associated with the digital communications system.