6.6 Modulation for the 3.84Mcps and 7.68Mcps options

25.2233GPPRelease 17Spreading and modulation (TDD)TS

The complex-valued chip sequence is modulated as shown in figure 3.

Figure 3: Modulation of complex valued chip sequences

The pulse-shaping characteristics are described in [9] and [10].

6.6.1 Combination of physical channels in uplink

Figure 4 illustrates the principle of combination of two different physical uplink channels within one timeslot. In the case of E-PUCH, only a single uplink physical channel is transmitted per timeslot and the procedures of subclause 6.6.1a shall instead apply).

The DPCHs to be combined belong to same CCTrCH, did undergo spreading as described in sections before and are thus represented by complex-valued sequences. First, the amplitude of all DPCHs is adjusted according to UL open loop power control as described in [10]. Each DPCH is then separately weighted by a weight factor _i and combined using complex addition. After combination of Physical Channels the gain factor _j is applied, depending on the actual TFC as described in [10].

In case of different CCTrCH, principle shown in Figure 4 applies to each CCTrCH separately.

Figure 4: Combination of different physical channels in uplink

The values of weight factors _i are depending on the spreading factor SF of the corresponding DPCH:

SF of DPCHi	i
32
16
8
4
2
1

NOTE: in the above table, SF = 32 is only supported in the 7.68Mcps TDD option.

In the case that _j (corresponding to the j–th TFC) has been explicitly signalled to the UE, the possible values that _j can assume are listed in the table below. In the case that _j has been calculated by the UE from a reference TFC, _j shall not be restricted to the quantised values.

Signalling value for j	Quantized value j
15	16/8
14	15/8
13	14/8
12	13/8
11	12/8
10	11/8
9	10/8
8	9/8
7	8/8
6	7/8
5	6/8
4	5/8
3	4/8
2	3/8
1	2/8
0	1/8

6.6.1a Physical channel transmission for E-PUCH

Figure 4a illustrates the principle of E-PUCH transmission. In a timeslot in which an E-PUCH is transmitted by a UE, no other physical channels may be transmitted by the same UE.

The amplitude of the E-PUCH is adjusted in accordance with the E-PUCH UL power control procedure described in [12]. The power setting procedure of [12] includes appropriate power adjustment factors for the E-PUCH spreading factor and for the E-TFC selected by higher layers [13]. Quantisation of the gain factor used to set the E-PUCH power is not specified.

Figure 4a: Combination of different physical channels in uplink

6.6.2 Combination of physical channels in downlink

Figure 5 illustrates how different physical downlink channels are combined within one timeslot. Each complex-valued spread channel is separately weighted by a weight factor G_i. If a timeslot contains the SCH, the complex-valued SCH, as described in [7] is separately weighted by a weight factor G_SCH. All downlink physical channels are then combined using complex addition.

Figure 5: Combination of different physical channels in downlink in case of SCH timeslot

6.6.3 Combination of signature sequences for E-HICH

Multiple HARQ acknowledgement indicator signature sequences may be mapped onto the same channelisation code. Each signature sequence (described in [8]) is first subjected to QPSK modulation as described in subclause 5.2.1.1 to form the output sequence for the h^th indicator sequence, where n=1,2,…,N_k and i=1,2. Code k is the same value for all signature sequences mapped to the same channelisation code.

When multiple signature sequences are to be transmitted on the same channelisation code, the following procedure shall be applied prior to spreading.

Each QPSK-modulated stream is amplitude-weighted by a factor g_h according to the desired signature sequence power. A summation is then performed across all H signature sequences mapped to the same channelisation code as shown in figure 5a. The output of the summation block is the sequence:

(n = 1,2,…,N_k) and (i=1,2) (8)

Figure 5a: Combination of HARQ acknowledgement indicator sequences prior to spreading

The sequence is mapped to a single channelisation code and subject to spreading at SF=16 (for 3.84Mcps) and at SF=32 (for 7.68Mcps) in accordance with the general method of subclause 6.