Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit a first transport block including a first uplink grant which schedules a first set of uplink shared channel transmissions for the UE. The base station may monitor the channel to detect an energy value for a demodulation reference signal (DMRS) associated with the one or more uplink shared channel transmissions associated with the first uplink grant that is less than a threshold energy value. Based on the relatively low DMRS energy, the base station may modify a size of a second transport block relative to the first transport block, the second transport block including a second uplink grant that schedules a second set of one or more uplink shared channel transmissions for the UE. The base station may then signal the grant for the modified second transport block to the UE or to another device.