urst types Burst 1 type with no TFCI applies Utilizes bursts type 1 and 2 with Training se- Time slots carrying P-CCPCH The training sequences described in quences, i.e. transmission use midambles m ¹, [6] apply to the S-CCPCH midambles m², m (9) and m (10 in order to sup- port block STTD antenna diversity and the beacon function; see a de- scription in [6. Block STTD Its support is mandatory for the UE antenna diver- as follows: (1) if no antenna diver- sity, it uses m (1) while m² remains unused; (2) if in block STTD an- tenna diversity exists, the first an- tenna uses m ¹ and the diversity antenna uses m² The UMTS Network and Radio Access Technology 4.4.5 The Physical Random Access Channel (PRACH) The RACH maps onto one or more uplink physical random access channels (PRACH) affording thereby flexible and scalable capacity to the RACH. PRACH Spreading The uplink PRACH uses either spreading factor SF = 16 or SF = 8, where the BCH broadcasts the set of admissible spreading codes and the associated spreading factors. Burst types Mobiles send uplink access bursts randomly through the PRACH, which has a burst consisting of two data symbol fields, a midamble and a guard period as seen in Figure 4.44. The 2nd data symbol field has only 880 chips instead 976 to allow larger guard time [6]. The collision groups depend on the selected RACH configuration. For example, with SF = 8, the first data field has 122 symbols and the second 110. Likewise, with SF = 16, field1 has 61 and field2 55 symbols, re- spectively. Table 7 in [6] illustrates the PRACH burst field content. Training Se- Different active users in the same time slot have time-shifted TS or mid- quences (TS) amble versions of single periodic basic code described in [6]. We choose time shifts from all k = 1,2,3...,K" (for cells with small radius) or uneven k = 1,3,5, (for cells with large radius). TS and channeli- We base the generic rule to define this association on the channelization zation code asso- codes CQ (k) order given by k and midambles m, (k) order giv