The maximum rank of the non-codebook based UL MIMO depends on the number of SRS resources in a SRS resource set, which is configured per BWP. The network can configure different number of SRS resources in a SRS resource set for each BWP to dynamic adapt to the maximum number of MIMO layers per BWP. Proposal 1: The maximum number of MIMO layers have been supported per BWP in Rel-15 for codebook based UL MIMO by configured the maxRank in the PUSCH-configured per BWP or non-codebook based UL MIMO by configured the number of SRS resources in a SRS resource set per BWP.