A multiple-access digital radio communication system and method with communication links between user terminal transmitters and a central node with a receiver system including a multibeam antenna. User terminal transmitters assigned to one beam coverage region use multiple access channels that are mutually orthogonal for transmitting digital message information that is included in a data group. Assignments are random and are changed for successive data groups. The same multiple access channels are reused in adjacent and other beam coverage regions each with an independent random assignment algorithm. Error-correction coding and interleaving are used in the user transmitter and an adaptive processor is used in the receiver. A reference sequence unique to either each user or each beam coverage region is multiplexed into user data groups for transmission. At the receiver the adaptive processor such as an equalizer or sequence estimator is used to combine multiple antenna beam signals to produce a combined signal associated with each user. The combining in the adaptive processor reduces interference from user terminal transmitters associated with different beam coverage regions but with the same multiple access channel. Deinterleaving and error-correction decoding of the combined signal are used to protect against channel assignments with larege mutual interference levels. The communication system can reuse each orthogonal multiple access channel in all of the other beams, i.e., a reuse factor of unity for each multiple access channel.