Here, as {HEAD ~ the number} of types of CAZAC sequences used for the reference signal is small, {TAIL ~ a sequence} specific to each cell is allocated 
Here , as { HEAD ~ the number } of types of CAZAC sequences used for the reference signal is small , { TAIL ~ a sequence } specific to each cell is allocated
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH