Apparatus and methods for uplink mimo enhancement in wireless systems

A computerized method for operating a millimeter wave (mmWave)-enabled wireless user device within a wireless network comprising at least one wireless access node, the computerized method comprising:

• measuring, by the mmWave-enabled wireless user device, an uplink channel condition associated with data communication with the at least one wireless access node;
• determining, based on the measured uplink channel condition, a channel rank or number of spatial layers supportable for uplink multiple input multiple output (MIMO) transmission;
• transmitting, to the at least one wireless access node, data representative of an indication of the determined channel rank or number of spatial layers;
• receiving, from the at least one wireless access node, configuration data identifying a selected number of spatial layers and a corresponding precoding matrix for an uplink transmission;
• and
• transmitting uplink data according to the selected number of spatial layers and the corresponding precoding matrix;
• wherein the configuration data specifies whether the user device operates in a transform-precoded (DFT-S-OFDM) mode or a non-transform (CP-OFDM) mode.

A computerized user device configured to operate within a MIMO (multiple input multiple output) transmission architecture employing a plurality of spatial layers, the computerized user device comprising:

• processor apparatus;
• at least one wireless interface in data communication with the processor apparatus, the at least one wireless interface comprising a plurality of spatial multiplexing layers and respective one or more antenna elements for each of the plurality of spatial multiplexing layers;
• and
• a storage device in data communication with the processor apparatus and comprising a storage medium configured to store at least one computer program, the at least one computer program configured to, when executed on the processor apparatus, cause the computerized user device to:
• measure a channel quality metric associated with an uplink channel;
• determine, based on the channel quality metric, a modification to a current uplink MIMO configuration, the modification comprising at least one of a change in a number of spatial layers or a change in a precoding matrix;
• notify a base station of the modification using an uplink control indication;
• and
• transmit, via the configured-grant uplink resources, data using the modified uplink MIMO configuration prior to reception of an explicit reconfiguration command from the base station.

Computer readable apparatus comprising a non-transitory storage medium having at least one computer program stored thereon, the at least one computer program comprising a plurality of instructions configured to, when executed on a digital processing device of a wireless user device, cause the wireless user device to:

• measure a parameter associated with an uplink transmission channel;
• based at least in part on the measured parameter, cause configuration of the wireless user device for uplink transmission using a first number of spatial data layers and a first precoding matrix;
• transmit data on an uplink physical shared channel via use of the first number of spatial data layers and the first precoding matrix;
• monitor a quality parameter associated with the uplink physical shared channel;
• and
• based on the quality parameter, initiate or respond to a modification of the uplink configuration of the wireless user device to at least one of:
• (i) a second number of spatial data layers different from the first number of spatial data layers, or
• (ii) a second precoding matrix different from the first precoding matrix;
• wherein the modification comprises at least one of a modification commanded by a wireless access node or a modification initiated by the wireless user device for a configured-grant uplink transmission.