a digital time division multiple access radio communications system employs a digital information source for providing digital information , a transmitter for transmitting encoded digital information in a radio - frequency signal to a receiver which demodulates the encoded symbols into digital information to be utilized by an output device . the receiver , synchronizes , compensates for frequency drift , samples and divides the samples into halfslots of samples . the halfslots are subdivided into subslots numbered from 1 to n , where n represents the last received subslot . subslots 1 and n are demodulated into digital information in a forward and reverse direction , respectively with metrics calculated . if the metrics indicate a signal with a larger signal - to - noise ratio from subslot n , subslot n - 1 is demodulated in a reverse sense with another reverse metric calculated , and vice versa . this process of extending demodulation in the direction of greater signal strength is repeated until all subslots in the slot have been demodulated . a second embodiment passes through all subslots in a forward and reverse direction calculating subslot metrics . the subslot metrics are summed into a halfslot metrics . the best halfslot metric indicates the sense of demodulation of each subslot . the digital information is then dumped in the proper order and sense to an output device which utilizes the digital information resulting in increased performance during fade periods .