A Simple definition of PUSCH hopping is Hopping in LTE Uplink.
Physical Uplink Shared Channel (PUSCH): is used to carry on the uplink user data. QPSK, 16QAM and 64QAM are the modulation schemes supported on PUSCH.
PUSCH is mapped to Physical resource blocks in different ways depending on whether uplink frequency hopping is enabled or not. The mapping also differs for different types of hopping if uplink frequency hopping is enabled.
Different techniques that provide uplink diversity can be used in cases where channel dependent scheduling is not suitable.
Frequency hopping is one of the techniques that can be used to enhance diversity in the 3G LTE uplink.