Patent ID: 10165529

Abstract:
Embodiments are provided for efficient uplink multiple-input multiple-output (MIMO) transmission and retransmission schemes. The embodiments include determining transmission rank and stream for MIMO when there are pending retransmissions on one stream. When retransmitting previously failed transmitted data at a user device, the rank and stream are determined according to a relation between a defined minimum TBS and a TBS selected for transmission according to an enhanced dedicated channel (E-DCH) transport format combination (E-TFC) selection procedure. An embodiment method includes detecting, at a user device, failed transmission of data on a secondary stream. If the selected TBS is less than the minimum TBS, then the user device selects rank-1 for retransmitting, on the primary stream, the data in the failed transmission regardless of rank indication by the network. Otherwise, the user device selects rank-2 for retransmitting, on the secondary stream, the data given a rank-2 indication.