Method and apparatus for controlling data retransmission in multiuser MIMO system

An apparatus for controlling data retransmission in a multi-user system, the apparatus comprising:

• at least a processor, and
• a memory, communicatively associated with the processor with computer coded instructions stored therein, said instructions when executed by the processor causing the apparatus to perform:
• determine whether data transferred by any of multiple users are received unsuccessfully, wherein the multiple users share a same resource in a feedback channel for carrying feedback information of whether or not data transferred by respective users are received successfully;
• and
• when data transferred by any of the multiple users are received unsuccessfully, select, for data retransmission, a first retransmission mode or a second retransmission mode according to a predetermined scheme,
• wherein in the first retransmission mode, positive feedback is sent via the same resource to the multiple users, and adaptive retransmission is triggered for the users whose data are received unsuccessfully, and
• wherein in the second retransmission mode, negative feedback is sent via the same resource to the multiple users so that non-adaptive retransmission is triggered for the multiple users, and
• wherein the predetermined scheme is defined based on at least one of the following:
• a ratio of the number of users whose data are received successfully, to the number of the multiple users;
• an amount of available resources in a control channel;
• and
• a probability that resource collisions in the feedback channel occur.

A non-transitory computer readable storage medium storing computer coded instructions which, when executed on at least one processor, cause the at least one processor to:

• determine whether data transferred by any of multiple users are received unsuccessfully, wherein the multiple users share a same resource in a feedback channel for carrying feedback information of whether or not data transferred by respective users are received successfully;
• and
• when data transferred by any of the multiple users are received unsuccessfully, select, for data retransmission, a first retransmission mode or a second retransmission mode according to a predetermined scheme,
• wherein in the first retransmission mode, positive feedback is sent via the same resource to the multiple users, and adaptive retransmission is triggered for the users whose data are received unsuccessfully, and
• wherein in the second retransmission mode, negative feedback is sent via the same resource to the multiple users so that non-adaptive retransmission is triggered for the multiple users, and
• wherein the predetermined scheme is defined based on at least one of the following:
• a ratio of the number of users whose data are received successfully, to the number of the multiple users;
• an amount of available resources in a control channel;
• and
• a probability that resource collisions in the feedback channel occur.