8 Mapping of transport channels to physical channels for the 7.68 Mcps option

25.2213GPPPhysical channels and mapping of transport channels onto physical channels (TDD)Release 17TS

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

This clause describes the way in which transport channels are mapped onto physical resources, see figure 26.

Transport Channels	Physical Channels
DCH	Dedicated Physical Channel (DPCH)


BCH	Primary Common Control Physical Channel (P-CCPCH)

FACH	Secondary Common Control Physical Channel (S-CCPCH)
PCH

RACH	Physical Random Access Channel (PRACH)


USCH	Physical Uplink Shared Channel (PUSCH)

DSCH	Physical Downlink Shared Channel (PDSCH)

	Paging Indicator Channel (PICH)

	MBMS Indication Channel (MICH)

	Synchronisation Channel (SCH)

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

	Shared Control Channel for HS-DSCH (HS-SCCH)

	Shared Information Channel for HS-DSCH (HS-SICH)

E-DCH	E-DCH Physical Uplink Channel (E-PUCH)

	E-DCH Random Access Uplink Control Channel (E-RUCCH)

	E-DCH Absolute Grant Channel (E-AGCH)

	E-DCH Hybrid ARQ Indicator Channel (E-HICH)

Figure 26: Transport channel to physical channel mapping

8.1 Dedicated Transport Channels

8.1.1 The Dedicated Channel (DCH)

Mapping of dedicated transport channels to physical channels is identical to 3.84Mcps TDD cf. [6.1 Dedicated Transport Channels].

8.1.2 The Enhanced Uplink Dedicated Channel (E-DCH)

The enhanced uplink dedicated channel is mapped on one or several E-PUCH, see subclause 5B.4.12.

8.1.2.1 E-DCH/E-AGCH Association and Timing

The E-DCH is always associated with a number of E-DCH Absolute Grant Channels (E-AGCH) and with one or two hybrid ARQ indicator channels (E-HICH). A grant of E-DCH transmission resources may be transmitted to the UE on any one of the associated E-AGCH. All relevant Layer 1 control information related to an E-DCH TTI is transmitted in the associated E-AGCH and one of the E-HICHs.

The E-DCH related time slot information that is carried on the E-AGCH refers to the next valid E-PUCH allocation, which is given by the following limitation: There shall be an offset of n_E-AGCH  6 time slots between the E-AGCH carrying the E-DCH related information and the first indicated E-PUCH (in time) for a given UE. The E-DCH related time slot information shall not refer to two subsequent radio frames but shall always refer to either the same or the following radio frame, as illustrated in figure 27. Note that the figure only shows the E-AGCH that carries the E-DCH related information for the given UE.

Figure 27: Timing for E-AGCH and E-DCH for different radio frame configurations for a given UE

8.1.2.2 E-DCH/E-HICH Association and Timing

E-DCH operations within the cell are associated with one or two channelisation codes carrying E-HICH (E-HICH₁ and E-HICH₂). If the number of timeslots configured for E-DCH use is 7 or more (this corresponds to the length of the timeslot resource related information field on E-AGCH – see [7]), both E-HICH₁ and E-HICH₂ channelisation codes shall be configured by higher layers, otherwise only the channelisation code E-HICH₁ is configured.

A single instance of E-HICH₁ (and E-HICH₂ if configured) channelisation codes exist in the cell per E-DCH TTI (10ms). For a given UE, a HARQ acknowledgement indicator is synchronously linked with the E-DCH TTI transmission to which it relates. There is thus a one-to-one association between an E-DCH TTI transmission and its respective HARQ acknowledgment indicator on one of the associated E-HICHs.

For each channelisation code carrying E-HICH, the associated instance shall be the first instance of that channelisation code to occur after n_E-HICH timeslots have elapsed since the start of the last E-PUCH of the corresponding E-DCH TTI (see examples of figure 28). The value of n_E-HICH is configurable by higher layers within the range 4 to 44 timeslots.

Figure 28: Timing for E-DCH and E-HICH for a given UE

The HARQ acknowledgement indicator associated with an E-DCH transmission is transmitted using one of 240 signature sequences carried by one of the associated E-HICH channelisation codes. Which signature sequence r = 0, 1, 2,…239 and (in the case that two channelisation codes are configured for E-HICH) which channelisation code is used are calculated for each E-DCH resource allocation using the following information signalled on the associated E_AGCH:

– t₀ is the bit position (1…n_TRRI) of the first active timeslot in the timeslot resource related information bitmap (see [7]) on E-AGCH and where bit position 1 corresponds to the lowest-numbered timeslot

– q₀ is the allocated channelisation code index (1,2,3,…Q₀)

– Q₀ is the spreading factor of the allocated uplink channelisation code

The value r’ is first calculated as:

Then:

– if r’≤239, r = r’ and channelisation code E-HICH₁ is used

– if r’>239, r = (r’-240) and channelisation code E-HICH₂ is used.

8.2 Common Transport Channels

8.2.1 The Broadcast Channel (BCH)

The mapping of the broadcast channel (BCH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.1 The Broadcast Channel (BCH)].

8.2.2 The Paging Channel (PCH)

The mapping of the paging channel (PCH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.2 The Paging Channel (PCH)].

8.2.3 The Forward Channel (FACH)

The mapping of the forward access channel (FACH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.3 The Forward Access Channel (FACH)].

8.2.4 The Random Access Channel (RACH)

The mapping of the random access channel (RACH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.4 The Random Access Channel (RACH)].

8.2.5 The Uplink Shared Channel (USCH)

The mapping of the uplink shared channel (USCH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.5 The Uplink Shared Channel (USCH)].

8.2.6 The Downlink Shared Channel (DSCH)

The mapping of the downlink shared channel (DSCH) to physical channels is identical to 3.84Mcps TDD cf. [6.2.6 The Downlink Shared Channel (DSCH)].

8.2.7 The High Speed Downlink Shared Channel (HS-DSCH)

The high speed downlink shared channel is mapped on one or several HS-PDSCH, see subclause 5B.4.8.

8.2.7.1 HS-DSCH/HS-SCCH Association and Timing

The HS-DSCH/HS-SCCH association and timing is identical to 3.84Mcps TDD cf. [section 6.2.7.1 HS-DSCH/HS-SCCH Association and Timing] with the exception that the number of HS-SCCHs that are associated with an HS-DSCH for one UE can range from a minimum of one HS-SCCH (M=1) to a maximum of eight HS-SCCH (M=8).

8.2.7.2 HS-SCCH/HS-DSCH/HS-SICH Association and Timing

The HS-SCCH/HS-DSCH/HS-SICH association and timing is identical to 3.84Mcps TDD cf. [6.2.7.2 HS-SCCH/HS-DSCH/HS-SICH Association and Timing].

Annex A (normative):
Basic Midamble Codes for the 3.84 Mcps option