In current practice, faulted messages are typically discarded and a retransmission is requested. Forward error-correction codes (FEC) in 5G and 6G are bulky, resource-expensive, and often unable to resolve the problem. Disclosed are systems and methods for determining which specific message elements are faulted, so that just the faulted portion can be retransmitted, instead of the entire message. For example, the amplitudes of the I and Q branches, of each message element, can be compared to the calibrated amplitude levels of the modulation scheme. Any message element with a large amplitude deviation is suspect. Other factors, such as the SNR, can also be considered in evaluating the validity of each message element. Usually, all of the faulted message elements occupy just a portion of the message. Compact formats are disclosed specifying which portion of the message is to be retransmitted, thereby saving time, power, and background generation.