the amount of TS PDCH does not depend on the coding scheme (MCS-*)
if one PDCH is carrying “MCS-9” it means the the bitrate of this PDCH is 59.2kbps.
if one MS is using 4 PDCH @ MCS-9, then the MS gets a (theoretical) throughput of 59.2kbps * 4.
On the Abis interface, 1 TS PDCH will be mapped on “n” Abis 16kbps resources (=nibbles).
If MCS9, then 1 PDCH = 4.5 nibbles
If MCS-5, then 1 PDCH = 3 nibbles
If MCS1, then 1 PDCH = 1 nibble
the explanation is that 1 nibble = 16kbps, it carry only a static throughput. While the PDCH can carry a variable throughput.