5.3.3 Common downlink physical channels

25.2113GPPPhysical channels and mapping of transport channels onto physical channels (FDD)Release 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.3.3.1 Common Pilot Channel (CPICH)

The CPICH is a fixed rate (30 kbps, SF=256) downlink physical channel that carries a pre-defined bit sequence. Figure 13 shows the frame structure of the CPICH.

Figure 13: Frame structure for Common Pilot Channel

In case transmit diversity is used on P-CCPCH and SCH, the CPICH shall be transmitted from both antennas using the same channelization and scrambling code. In this case, the pre-defined bit sequence of the CPICH is different for Antenna 1 and Antenna 2, see figure 14. In case of no transmit diversity, the bit sequence of Antenna 1 in figure 14 is used.

Figure 14: Modulation pattern for Common Pilot Channel

There are two types of Common pilot channels, the Primary and Secondary CPICH. They differ in their use and the limitations placed on their physical features.

5.3.3.1.1 Primary Common Pilot Channel (P-CPICH)

The Primary Common Pilot Channel (P-CPICH) has the following characteristics:

– The same channelization code is always used for the P-CPICH, see [4];

– The P-CPICH is scrambled by the primary scrambling code, see [4];

– There is one and only one P-CPICH per cell;

– The P-CPICH is broadcast over the entire cell.

5.3.3.1.2 Secondary Common Pilot Channel (S-CPICH)

A Secondary Common Pilot Channel (S-CPICH) has the following characteristics:

– An arbitrary channelization code of SF=256 is used for the S-CPICH, see [4];

– An S-CPICH is scrambled by either the primary or a secondary scrambling code, see [4];

– There may be zero, one, or several S-CPICH per cell;

– An S-CPICH may be transmitted over the entire cell or only over a part of the cell;

– An S-CPICH that is intended to be used as phase reference for the second, third or fourth transmit antenna by UEs configured in MIMO mode or in MIMO mode with four transmit antennas shall be transmitted over the entire cell using the primary scrambling code and the antenna 1 pattern.

5.3.3.1.3 Demodulation Common Pilot Channel (D-CPICH)

A Demodulation Common Pilot Channel (D-CPICH) has the following characteristics:

– An arbitrary channelization code of SF=256 is used for the D-CPICH, see [4];

– A D-CPICH is scrambled by the primary scrambling code see [4];

– There may be zero or two D-CPICH per cell;

– A D-CPICH shall be transmitted over the entire cell;

– Carries a pre defined bit sequence same as that of Antenna 1 in Figure 14;

– A D-CPICH is non precoded and is transmitted from third or fourth transmit antenna;

– The UE for which the two D-CPICH are activated may assume that the D-CPICHs are present in the HS-DSCH TTIs in which the UE is scheduled to receive HS-PDSCHs.

5.3.3.2 Downlink phase reference

Table 17 specifies the channels which the UE may use as a phase reference for each downlink physical channel type in a cell; it also specifies whether the channels which the UE may use as a phase reference for a channel of a particular type shall be assumed to be the same as the ones which the UE may use as a phase reference for the associated DPCH or F-DPCH in the same cell, if configured.

For the DPCH or F-DPCH and the associated downlink physical channels the following always applies:

– The UE may use the DPCH pilot bits as a phase reference.

– In addition, the UE may use either the primary CPICH or a secondary CPICH as a phase reference.

– By default (i.e. without any indication by higher layers) the UE may use the primary CPICH as a phase reference.

– When a UE is not configured in MIMO mode and not in MIMO mode with four transmit antennas in a cell: The UE is informed by higher layers when it may use a secondary CPICH as a phase reference. In this case the UE shall not use the primary CPICH as a phase reference. Indication that a secondary CPICH may be a phase reference is also applicable when open loop or closed loop TX diversity is enabled for a downlink physical channel in which case Antenna 1 and Antenna 2 secondary CPICH shall be used as phase references.

– When the UE is configured in MIMO mode in a cell: The UE is informed by higher layers when it may use a secondary CPICH as a phase reference for a second transmit antenna in addition to the primary CPICH which will be transmitted from the first antenna. In addition, if the UE supports open loop Tx diversity on associated physical channels with the combination of primary CPICH and secondary CPICH, this combination of phase references can also be used as phase references for associated physical channels configured with open loop Tx diversity. If the UE does not support open loop Tx diversity on associated physical channels with the combination of primary CPICH and secondary CPICH and if secondary CPICH is used as a phase reference for second transmit antenna, UE may assume that associated physical channels are not in Tx diversity mode. If no secondary CPICH is signalled as phase reference, the UE may use the Antenna 1 and Antenna 2 primary CPICH as phase references.

– When the UE is configured in MIMO mode with four transmit antennas in a cell: The UE is informed by higher layers when it should use any of the secondary CPICH as a phase reference for a second, third or fourth transmit antenna in addition to the primary CPICH which will be transmitted from the first antenna. In addition, if the UE supports open loop Tx diversity on associated physical channels with the combination of primary CPICH and secondary CPICH on second transmit antenna, this combination of phase references can also be used as phase references for associated physical channels configured with open loop Tx diversity. If the UE does not support open loop Tx diversity on associated physical channels with the combination of primary CPICH and secondary CPICH, then the UE may assume that associated physical channels are not in Tx diversity mode.

Table 17: Phase references for downlink physical channel types in a cell
"X" – Applicable, "–" – Not applicable

Physical channel type	DPCH Dedicated pilot (never as the sole phase reference)	Primary -CPICH	Secondary -CPICH	Demodulation-CPICH	Same as associated DPCH or F‑DPCH
P-CCPCH	–	X	–	–	–
SCH	–	X	–	–	–
S-CCPCH	–	X	–	–	–
DPCH*	X	X	X	–	–
F-DPCH*	–	X	X	–	–
PICH	–	X	–	–	–
MICH	–	X	–	–	–
HS-PDSCH* (UE not in MIMO mode, not in MIMO mode with four transmit antennas and associated DPCH or F-DPCH is configured)	–	–	–	–	X
HS-PDSCH* (UE in MIMO mode)	–	X	X	–	–
HS-PDSCH** (UE in MIMO mode with four transmit antennas)	–	X	X	X	–
HS-PDSCH (if no associated DPCH or F-DPCH is configured)	–	X	–	–	–
HS-SCCH* (if associated DPCH or F-DPCH is configured)	–	–	–	–	X
HS-SCCH (if no associated DPCH or F-DPCH is configured)	–	X	–	–	–
E-AGCH*	–	–	–	–	X
E-RGCH* (if associated DPCH or F-DPCH is configured)	–	–	–	–	X
E-RGCH (if no associated DPCH or F-DPCH is configured)	–	X	–	–	–
E-HICH*	–	–	–	–	X
E-HICH (if no associated DPCH or F-DPCH is configured)	–	X	–	–	–
AICH	–	X	–	–	–
F-TPICH	–	–	–	–	X

Note *: A secondary CPICH should not be configured as a phase reference for DPCH or F-DPCH when a UE simultaneously receives S-CCPCHs on different radio links and DPCH or F-DPCH. The UE behavior is undefined if this configuration is used. The support for simultaneous reception of S-CCPCHs on different radio links and DPCH or F-DPCH is optional in the UE.

**: When the UE is configured in MIMO mode with four transmit antennas, Secondary CPICHs on Antennas 2, 3, and 4 and Demodulation CPICHs on Antennas 3 and 4 are used as phase reference.

Dedicated pilot bits are never the sole phase reference for any physical channel, but the UE may always use dedicated pilot bits as a phase reference for DPCH.

Furthermore, during a DPCH or F-DPCH frame overlapping with any part of an associated HS-DSCH or HS-SCCH subframe, the phase reference on this DPCH or F-DPCH shall not change.

5.3.3.3 Primary Common Control Physical Channel (P-CCPCH)

The Primary CCPCH is a fixed rate (30 kbps, SF=256) downlink physical channels used to carry the BCH transport channel.

Figure 15 shows the frame structure of the Primary CCPCH. The frame structure differs from the downlink DPCH in that no TPC commands, no TFCI and no pilot bits are transmitted. The Primary CCPCH is not transmitted during the first 256 chips of each slot. Instead, Primary SCH and Secondary SCH are transmitted during this period (see subclause 5.3.3.5).

Figure 15: Frame structure for Primary Common Control Physical Channel

5.3.3.3.1 Primary CCPCH structure with STTD encoding

In case the diversity antenna is present in UTRAN and the P-CCPCH is to be transmitted using open loop transmit diversity, the data bits of the P-CCPCH are STTD encoded as given in subclause 5.3.1.1.1. The last two data bits in even numbered slots are STTD encoded together with the first two data bits in the following slot, except for slot #14 where the two last data bits are not STTD encoded and instead transmitted with equal power from both the antennas, see figure 16. Higher layers signal whether STTD encoding is used for the P-CCPCH or not. In addition the presence/absence of STTD encoding on P-CCPCH is indicated by modulating the SCH, see 5.3.3.4. During power on and hand over between cells the UE can determine the presence of STTD encoding on the P-CCPCH, by either receiving the higher layer message, by demodulating the SCH channel, or by a combination of the above two schemes.

Figure 16: STTD encoding for the data bits of the P-CCPCH

5.3.3.4 Secondary Common Control Physical Channel (S-CCPCH)

The Secondary CCPCH is used to carry the FACH and PCH, and can also be configured to carry a BCH. There are two types of Secondary CCPCH: those that include TFCI and those that do not include TFCI. It is the UTRAN that determines if a TFCI should be transmitted, hence making it mandatory for all UEs to support the use of TFCI. The set of possible rates for the Secondary CCPCH is the same as for the downlink DPCH, see subclause 5.3.2. The frame structure of the Secondary CCPCH is shown in figure 17.

Figure 17: Frame structure for Secondary Common Control Physical Channel

The parameter k in figure 17 determines the total number of bits per downlink Secondary CCPCH slot. It is related to the spreading factor SF of the physical channel as SF = 256/2^k. The spreading factor range is from 256 down to 4.

The values for the number of bits per field are given in Table 18. The channel bit and symbol rates given in Table 18 are the rates immediately before spreading. The slot formats applicable to QPSK with pilot bits are not supported in this release. The pilot patterns for the slot formats applicable to QPSK are given in Table 19. DTX shall be used in the pilot field of the 16QAM slot formats, i.e. no pilot bits are used in this release. A BCH mapped to Secondary CCPCH uses the specific fixed Secondary CCPCH slot format in Table 18, and this slot format can only be used for carrying BCH.

The FACH and PCH can be mapped to the same or to separate Secondary CCPCHs. If FACH and PCH are mapped to the same Secondary CCPCH, they can be mapped to the same frame. A BCH mapped to Secondary CCPCH can only be mapped to a separate Secondary CCPCH without multiplexing with other transport channels. The main difference between a CCPCH and a downlink dedicated physical channel is that a CCPCH is not inner-loop power controlled. The main difference between the Primary and Secondary CCPCH is that the transport channel mapped to the Primary CCPCH (BCH) can only have a fixed predefined transport format combination, while the Secondary CCPCH supports multiple transport format combinations on the transport channels mapped to it and offers the possibility of using TFCI.

Table 18: Secondary CCPCH fields

Slot Format #i	Channel Bit Rate (kbps)	Channel Symbol Rate (ksps)	SF	Bits/ Frame	Bits/ Slot	N_data1	N_pilot	N_TFCI
0	30	15	256	300	20	20	0	0
1	30	15	256	300	20	12	8	0
2	30	15	256	300	20	18	0	2
3	30	15	256	300	20	10	8	2
4	60	30	128	600	40	40	0	0
5	60	30	128	600	40	32	8	0
6	60	30	128	600	40	38	0	2
7	60	30	128	600	40	30	8	2
8	120	60	64	1200	80	72	0	8*
9	120	60	64	1200	80	64	8	8*
10	240	120	32	2400	160	152	0	8*
11	240	120	32	2400	160	144	8	8*
12	480	240	16	4800	320	312	0	8*
13	480	240	16	4800	320	296	16	8*
14	960	480	8	9600	640	632	0	8*
15	960	480	8	9600	640	616	16	8*
16	1920	960	4	19200	1280	1272	0	8*
17	1920	960	4	19200	1280	1256	16	8*
18***	60	15	256	600	40	36	0	4
19***	120	30	128	1200	80	76	0	4
20***	240	60	64	2400	160	144	0	16*
21***	480	120	32	4800	320	272	32**	16*
22***	960	240	16	9600	640	560	64**	16*
23***	1920	480	8	19200	1280	1136	128**	16*
BCH****	30	15	256	300	20	18	0	0

* If TFCI bits are not used, then DTX shall be used in TFCI field.

** If pilot bits are not used, then DTX shall be used in pilot field.

*** Slot formats applicable to 16QAM. See subclause 4.3.5.1.1 in [3] for mapping TFCI bits on 16QAM slot formats.

**** Slot format used for S-CCPCH carrying BCH. The first two data bits (256 chips) out of the 20 data bits in each slot are DTXed, resulting in a frame structure identical to P-CCPCH.

NOTE 1: The slot formats 18 to 23 in Table 18 are only applicable for MBSFN operations with 16QAM.

NOTE 2: The modulation used in MBSFN operations is signalled by higher layers.

The pilot symbol pattern described in Table 19 is not supported in this release. The shadowed part can be used as frame synchronization words. (The symbol pattern of pilot symbols other than the frame synchronization word shall be "11"). In Table 19, the transmission order is from left to right. (Each two-bit pair represents an I/Q pair of QPSK modulation.)

Table 19: Pilot Symbol Pattern

Npilot = 8

Npilot = 16

Symbol #

Slot #0

For slot formats using TFCI, the TFCI value in each radio frame corresponds to a certain transport format combination of the FACHs and/or PCHs currently in use. This correspondence is (re-)negotiated at each FACH/PCH addition / removal. The mapping of the TFCI bits onto slots is described in [3].

5.3.3.4.1 Secondary CCPCH structure with STTD encoding

In case the diversity antenna is present in UTRAN and the S-CCPCH does not carry BCH and is to be transmitted using open loop transmit diversity, the data and TFCI bits of the S-CCPCH are STTD encoded as given in subclause 5.3.1.1.1. The pilot symbol pattern for antenna 2 for the S-CCPCH given in Table 20 is not supported in this release. If S-CCPCH carries BCH and open loop transmit diversity is to be applied, the STTD encoding is done the same way as for P-CCPCH as described in subclause 5.3.3.3.1.

Table 20: Pilot symbol pattern for antenna 2 when STTD encoding is used on the S‑CCPCH

Npilot = 8

Npilot = 16

Symbol #

Slot #0

5.3.3.5 Synchronisation Channel (SCH)

The Synchronisation Channel (SCH) is a downlink signal used for cell search. The SCH consists of two sub channels, the Primary and Secondary SCH. The 10 ms radio frames of the Primary and Secondary SCH are divided into 15 slots, each of length 2560 chips. Figure 18 illustrates the structure of the SCH radio frame.

Figure 18: Structure of Synchronisation Channel (SCH)

The Primary SCH consists of a modulated code of length 256 chips, the Primary Synchronisation Code (PSC) denoted c_p in figure 18, transmitted once every slot. The PSC is the same for every cell in the system.

The Secondary SCH consists of repeatedly transmitting a length 15 sequence of modulated codes of length 256 chips, the Secondary Synchronisation Codes (SSC), transmitted in parallel with the Primary SCH. The SSC is denoted c_s^i,k in figure 18, where i = 0, 1, …, 63 is the number of the scrambling code group, and k = 0, 1, …, 14 is the slot number. Each SSC is chosen from a set of 16 different codes of length 256. This sequence on the Secondary SCH indicates which of the code groups the cell’s downlink scrambling code belongs to.

The primary and secondary synchronization codes are modulated by the symbol a shown in figure 18, which indicates the presence/ absence of STTD encoding on the P-CCPCH and is given by the following table:

P-CCPCH STTD encoded	a = +1
P-CCPCH not STTD encoded	a = -1

5.3.3.5.1 SCH transmitted by TSTD

Figure 19 illustrates the structure of the SCH transmitted by the TSTD scheme. In even numbered slots both PSC and SSC are transmitted on antenna 1, and in odd numbered slots both PSC and SSC are transmitted on antenna 2.

Figure 19: Structure of SCH transmitted by TSTD scheme

5.3.3.6 Void

5.3.3.7 Acquisition Indicator Channel (AICH)

The Acquisition Indicator channel (AICH) is a fixed rate (SF=256) physical channel used to carry Acquisition Indicators (AI) and Extended Acquisition Indicators (EAI). Acquisition Indicator AI_s corresponds to signature s on the PRACH. Extended Acquisition Indicators represent a set of values corresponding to a set of E-DCH resource configurations.

Figure 21 illustrates the structure of the AICH. The AICH consists of a repeated sequence of 15 consecutive access slots (AS), each of length 5120 chips. Each access slot consists of two parts, an Acquisition-Indicator (AI) part consisting of 32 real-valued signals a₀, …, a₃₁ and a part of duration 1024 chips with no transmission that is not formally part of the AICH. The part of the slot with no transmission is reserved for possible future use by other physical channels.

The spreading factor (SF) used for channelisation of the AICH is 256.

The phase reference for the AICH is the Primary CPICH.

Figure 21: Structure of Acquisition Indicator Channel (AICH)

The real-valued signals a₀, a₁, …, a₃₁ in figure 21 are given by

where AI_s, taking the values +1, -1, and 0, is the acquisition indicator corresponding to signature s and the sequence b_s,0, …, b_s,31 is given by Table 22, EAI_s’, taking the values +1, -1, and 0, is the extended acquisition indicator corresponding to signature s’ and the sequence c_s’,0, …, c_s’,31 is given by Table 22B. The EAI_s’ has the same relative transmit power as the AI_s; the relative transmit power is indicated by higher layers. If the signature s is not a member of the set of available signatures for all the Access Service Class (ASC) for the corresponding PRACH (cf [5]) then AI_s shall be set to 0.

The use of acquisition indicators is described in [5]. The meaning of acquisition indicators depends on whether a UE sends an access preamble signature corresponding to a PRACH message or corresponding to an E-DCH transmission. Furthermore, if a UE sends an access preamble signature corresponding to an E-DCH transmission, the meaning of the acquisition indicator depends on whether EAI is configured or not. The following rules apply for one PRACH preamble scrambling code. If multiple PRACH preamble scrambling codes are defined in a cell, then for each of them the following rules are used independently.

– If the UE sends an access preamble signature corresponding to a PRACH message, then;

– if an Acquisition Indicator is set to +1, it represents a positive acknowledgement,

– if an Acquisition Indicator is set to -1, it represents a negative acknowledgement.

– If the UE sends an access preamble signature corresponding to an E-DCH transmission, then;

– if the corresponding Acquisition Indicator is set to +1, it represents a positive acknowledgement and the associated default E-DCH resource configuration is allocated to the UE,

– if the corresponding Acquisition Indicator is set to -1 and EAI is not configured, then it represents a negative acknowledgement,

– if the corresponding Acquisition Indicator is set to -1 and EAI is configured, then the UE detects which one of the Extended Acquisition Indicator signatures is present.

The association between the AI and the default E-DCH resource index is such that, for 10 ms TTI length:

X = SigInd mod Y,

The association between the AI and the default E-DCH resource index is such that, for 2 ms TTI length:

X = (SigInd mod (Y – Concurrent TTI partition Index)) + Concurrent TTI partition Index,

where X is the Default E-DCH resource index, "Concurrent TTI partition Index" is signalled by higher layers or otherwise is set to zero, Y is the total number of E-DCH resources configured in the cell for Enhanced Uplink in CELL_FACH state and IDLE mode, and SigInd is the Nth PRACH preamble signature corresponding to the AI that is configured available in the cell and corresponding to E-DCH transmission for Enhanced Uplink in CELL_FACH state and IDLE mode. PRACH preamble signatures are renumbered as specified in [17] subclause 8.6.6.29.

The use of Extended Acquisition Indicators is described in [5]. If s’=0 and an EAI₀ is set to +1, it represents a negative acknowledgement. The mapping between the non-zero EAI_s’ and the E-DCH resource configuration index is presented in Table 22A where X is the index of the default E-DCH resource as defined above and Y is the total number of E-DCH resources configured in the cell.

The real-valued signals, a_j, are spread and modulated in the same fashion as bits when represented in {+1, -1 } form.

In case STTD-based open-loop transmit diversity is applied to AICH, STTD encoding according to subclause 5.3.1.1.1 is applied to each sequence b_s,0, b_s,1, …, b_s,31 separately and sequence c_s’,0, c_s’,1, …, c_s’,31 before the sequences are combined into AICH signals a₀, …, a₃₁.

Table 22: AI signature patterns

s	b_s,0, b_s,1…, b_s,31
0	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1
2	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1
3	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1
4	1	1	1	1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1
5	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1
6	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1
7	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1
8	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1
9	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1
10	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1
11	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1
12	1	1	1	1	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1	1	1	1	1
13	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1	1	1	-1	-1
14	1	1	1	1	-1	-1	-1	-1	-1	-1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	1	1	1	1	-1	-1	-1	-1
15	1	1	-1	-1	-1	-1	1	1	-1	-1	1	1	1	1	-1	-1	-1	-1	1	1	1	1	-1	-1	1	1	-1	-1	-1	-1	1	1

Table 22A: EAI and resource configuration mapping

EAI_s’	Signature s’	E-DCH Resource configuration index
+1	0	NACK
-1	0	(X + 1) mod Y
+1	1	(X + 2) mod Y
-1	1	(X + 3) mod Y
+1	2	(X + 4) mod Y
-1	2	(X + 5) mod Y
+1	3	(X + 6) mod Y
-1	3	(X + 7) mod Y
+1	4	(X + 8) mod Y
-1	4	(X + 9) mod Y
+1	5	(X + 10) mod Y
-1	5	(X + 11) mod Y
+1	6	(X + 12) mod Y
-1	6	(X + 13) mod Y
+1	7	(X + 14) mod Y
-1	7	(X + 15) mod Y
+1	8	(X + 16) mod Y
-1	8	(X + 17) mod Y
+1	9	(X + 18) mod Y
-1	9	(X + 19) mod Y
+1	10	(X + 20) mod Y
-1	10	(X + 21) mod Y
+1	11	(X + 22) mod Y
-1	11	(X + 23) mod Y
+1	12	(X + 24) mod Y
-1	12	(X + 25) mod Y
+1	13	(X + 26) mod Y
-1	13	(X + 27) mod Y
+1	14	(X + 28) mod Y
-1	14	(X + 29) mod Y
+1	15	(X + 30) mod Y
-1	15	(X + 31) mod Y

Table 22B: EAI signature patterns

s’	c_s’,0, c_s’,1…, c_s’,31
0	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1
1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1
2	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1
3	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1
4	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1
5	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1
6	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1
7	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1
8	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1
9	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1
10	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1
11	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1
12	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1	1	-1	1	-1
13	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1	1	-1	-1	1
14	1	-1	1	-1	-1	1	-1	1	-1	1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	1	-1	1	-1	-1	1	-1	1
15	1	-1	-1	1	-1	1	1	-1	-1	1	1	-1	1	-1	-1	1	-1	1	1	-1	1	-1	-1	1	1	-1	-1	1	-1	1	1	-1

5.3.3.8 Void

5.3.3.9 Void

5.3.3.10 Paging Indicator Channel (PICH)

The Paging Indicator Channel (PICH) is a fixed rate (SF=256) physical channel used to carry the paging indicators. The PICH is associated either with an S-CCPCH to which a PCH transport channel is mapped, or with a HS-SCCH associated with the HS-PDSCH(s) to which a HS-DSCH transport channel carrying paging messages is mapped.

Figure 24 illustrates the frame structure of the PICH. One PICH radio frame of length 10 ms consists of 300 bits (b₀, b₁, …, b₂₉₉). Of these, 288 bits (b₀, b₁, …, b₂₈₇) are used to carry paging indicators. The remaining 12 bits are not formally part of the PICH and shall not be transmitted (DTX). The part of the frame with no transmission is reserved for possible future use.

Figure 24: Structure of Paging Indicator Channel (PICH)

In each PICH frame, Np paging indicators {P₀, …, P_Np-1} are transmitted, where Np=18, 36, 72, or 144.

The PI calculated by higher layers for use for a certain UE, is associated to the paging indicator P_q, where q is computed as a function of the PI computed by higher layers, the SFN of the P-CCPCH radio frame during which the start of the PICH radio frame occurs, and the number of paging indicators per frame (Np):

Further, the PI calculated by higher layers is associated with the value of the paging indicator P_q. If a paging indicator in a certain frame is set to "1" it is an indication that UEs associated with this paging indicator and PI should read either the corresponding frame of the associated S-CCPCH, or the corresponding subframes of the associated HS-SCCH

The PI bitmap in the PCH data frames over Iub contains indication values for all higher layer PI values possible. Each bit in the bitmap indicates if the paging indicator associated with that particular PI shall be set to 0 or 1. Hence, the calculation in the formula above is to be performed in Node B to make the association between PI and P_q.

The mapping from {P₀, …, P_Np-1} to the PICH bits {b₀, …, b₂₈₇} are according to Table 24.

Table 24: Mapping of paging indicators P_q to PICH bits

Number of paging indicators per frame (Np)	P_q = 1	P_q = 0
Np=18	{b_16q, …, b_16q+15} = {1, 1,…, 1}	{b_16q, …, b_16q+15} = {0, 0,…, 0}
Np=36	{b_8q, …, b_8q+7} = {1, 1,…, 1}	{b_8q, …, b_8q+7} = {0, 0,…, 0}
Np=72	{b_4q, …, b_4q+3} = {1, 1,…, 1}	{b_4q, …, b_4q+3} = {0, 0,…, 0}
Np=144	{b_2q, b_2q+1} = {1, 1}	{b_2q, b_2q+1} = {0, 0}

When transmit diversity is employed for the PICH, STTD encoding is used on the PICH bits as described in subclause 5.3.1.1.1.

5.3.3.11 Void

5.3.3.12 Shared Control Channel (HS-SCCH)

The HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to carry downlink signalling related to HS-DSCH transmission. Figure 26A illustrates the sub-frame structure of the HS-SCCH.

Figure 26A: Subframe structure for the HS-SCCH

5.3.3.13 High Speed Physical Downlink Shared Channel (HS-PDSCH)

The High Speed Physical Downlink Shared Channel (HS- PDSCH) is used to carry the High Speed Downlink Shared Channel (HS-DSCH).

A HS-PDSCH corresponds to one channelization code of fixed spreading factor SF=16 from the set of channelization codes reserved for HS-DSCH transmission. Multi-code transmission is allowed, which translates to UE being assigned multiple channelisation codes in the same HS-PDSCH subframe, depending on its UE capability.

The subframe and slot structure of HS-PDSCH are shown in figure 26B.

Figure 26B: Subframe structure for the HS-PDSCH

An HS-PDSCH may use QPSK, 16QAM or 64QAM modulation symbols. In figure 26B, M is the number of bits per modulation symbols i.e. M=2 for QPSK, M=4 for 16QAM and M=6 for 64QAM. The slot formats are shown in table 26.

Table 26: HS-DSCH fields

Slot format #i	Channel Bit Rate (kbps)	Channel Symbol Rate (ksps)	SF	Bits/ HS-DSCH subframe	Bits/ Slot	Ndata
0(QPSK)	480	240	16	960	320	320
1(16QAM)	960	240	16	1920	640	640
2(64QAM)	1440	240	16	2880	960	960

All relevant Layer 1 information is transmitted in the associated HS-SCCH i.e. the HS-PDSCH does not carry any Layer 1 information.

5.3.3.14 E–DCH Absolute Grant Channel (E-AGCH)

An E-DCH Absolute Grant Channel (E-AGCH) is a fixed rate (30 kbps, SF=256) downlink physical channel carrying uplink E-DCH absolute grants for uplink E-DCHs associated with the E-AGCH by higher layer signalling. Figure 26C illustrates the frame and sub-frame structure of the E‑AGCH.

An E-DCH absolute grant shall be transmitted over one E-AGCH sub-frame or one E-AGCH frame. The transmission over one E-AGCH sub-frame and over one E-AGCH frame shall be used for UEs for which E-DCH TTI is set to respectively 2 ms and 10 ms.

Figure 26C: Sub-frame structure for the E-AGCH

5.3.3.14B E-DCH Rank and Offset Channel (E-ROCH)

An E-DCH Rank and Offset Channel (E-ROCH) has the same sub-frame structure as the E-AGCH defined in section 5.3.3.14. The transmission shall always take place over one E-ROCH sub-frame. The E-ROCH is only transmitted to a UE for which the E-DCH TTI is set to 2 ms and the UL_MIMO_Enabled is set to TRUE.

The E-ROCH and E-AGCH can only be transmitted simultaneously to a UE if they are configured with different channelization codes.

5.3.3.15 MBMS Indicator Channel (MICH)

The MBMS Indicator Channel (MICH) is a fixed rate (SF=256) physical channel used to carry the MBMS notification indicators. The MICH is always associated with an S-CCPCH to which a FACH transport channel is mapped.

Figure 26D illustrates the frame structure of the MICH. One MICH radio frame of length 10 ms consists of 300 bits (b₀, b₁, …, b₂₉₉). Of these, 288 bits (b₀, b₁, …, b₂₈₇) are used to carry notification indicators. The remaining 12 bits are not formally part of the MICH and shall not be transmitted (DTX).

Figure 26D: Structure of MBMS Indicator Channel (MICH)

In each MICH frame, Nn notification indicators {N₀, …, N_Nn-1} are transmitted, where Nn=18, 36, 72, or 144.

The NI calculated by higher layers is associated to the index q of the notification indicator N_q, where q is computed as a function of the NI computed by higher layers, the SFN of the P-CCPCH radio frame during which the start of the MICH radio frame occurs, and the number of notification indicators per frame (Nn):

where G = 2¹⁶ , C = 25033 and NI is the 16 bit Notification Indicator calculated by higher layers.

The set of NI signalled over Iub indicates all higher layer NI values for which the associated notification indicator on MICH shall be set to 1 during the corresponding modification period. Hence, the calculation in the formula above shall be performed in the Node B every MICH frame for each NI signalled over Iub to make the association between NI and q and set the related N_q to 1. All other notification indicators on MICH shall be set to 0.

The mapping from {N₀, …, N_Nn-1} to the MICH bits {b₀, …, b₂₈₇} are according to table 27.

Table 27: Mapping of notification indicators N_q to MICH bits

Number of notification indicators per frame (Nn)	N_q = 1	N_q = 0
Nn=18	{b_16q, …, b_16q+15} = {1, 1,…, 1}	{b_16q, …, b_16q+15} = {0, 0,…, 0}
Nn=36	{b_8q, …, b_8q+7} = {1, 1,…, 1}	{b_8q, …, b_8q+7} = {0, 0,…, 0}
Nn=72	{b_4q, …, b_4q+3} = {1, 1,…, 1}	{b_4q, …, b_4q+3} = {0, 0,…, 0}
Nn=144	{b_2q, b_2q+1} = {1, 1}	{b_2q, b_2q+1} = {0, 0}

When transmit diversity is employed for the MICH, STTD encoding is used on the MICH bits as described in subclause 5.3.1.1.1.

5.3.3.16 Common E-DCH Relative Grant Channel

The Common E-RGCH is a downlink physical channel for UEs in CELL_FACH state as described in sub clause 6B.2 of [5]. There is no DPCH or F-DPCH associated with the Common E-RGCH.

The structure, STTD encoding and timing relationship of the Common E-RGCH follow the rules of the dedicated E‑RGCH for which the cell transmitting the E-RGCH is not in the E-DCH serving radio link set (sub clause 5.3.2.4 and 7.11).