R R ESOURCE ESOURCE M M APPING APPING 4-16 4-

4.5 RRESOURCEESOURCEMMAPPINGAPPING... 4-164-16

4.5.1

4.5.1 Resource DefinResource Definitionsitions ...4-16...4-16 4.5.2

4.5.2 Downlink SubfraDownlink Subframeme ...4-17...4-17 4.5.3

4.5.3 Downlink Downlink Cell Search Cell Search PatternPattern ...4-19...4-19 4.5.4

4.5.4 Uplink SubframeUplink Subframe: PUSCH: PUSCH ...4-19...4-19 4.5.5

4.5.5 Uplink Subframe: PUCCH...4-20Uplink Subframe: PUCCH...4-20

4.6

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4.1 Introduction

The E-UTRA physical layer (PHY) offers a highly efficient means of The E-UTRA physical layer (PHY) offers a highly efficient means of conveying data and control information between the eNodeB and the UE. conveying data and control information between the eNodeB and the UE. The E-UTRA PHY employs some advanced technologies that are quite The E-UTRA PHY employs some advanced technologies that are quite new to cellular

new to cellular applications. These include Orthogonal Frequency Divisionapplications. These include Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) data Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) data transmission, as described in chapters 2 and

transmission, as described in chapters 2 and 3.3.

On the other hand, the LTE standardisation project aims at reusing legacy On the other hand, the LTE standardisation project aims at reusing legacy solutions wherever possible. A reader who is familiar with the UTRAN solutions wherever possible. A reader who is familiar with the UTRAN channel and protocol architecture will therefore feel quite ‘at home’ with channel and protocol architecture will therefore feel quite ‘at home’ with the E-UTRAN channel and protocol

the E-UTRAN channel and protocol architecture. The LTE standardisationarchitecture. The LTE standardisation project also aims at reducing the overall system complexity, resulting in a project also aims at reducing the overall system complexity, resulting in a simplified layered architecture as compared to UTRAN.

simplified layered architecture as compared to UTRAN.

The E-UTRA specifications describe both Frequency Division Duplex The E-UTRA specifications describe both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) to separate UL and DL traffic. (FDD) and Time Division Duplex (TDD) to separate UL and DL traffic. The overall channel architecture, layer 1 processing chain and resource The overall channel architecture, layer 1 processing chain and resource mapping is the same for both. Thus, the content in this chapter pertains to mapping is the same for both. Thus, the content in this chapter pertains to both FDD and TDD, unless otherwise stated. (The expected market both FDD and TDD, unless otherwise stated. (The expected market preferences dictate that the majority of deployed systems will be FDD.) preferences dictate that the majority of deployed systems will be FDD.) The generic radio frame structure (‘frame Type 1’) and the TDD specific The generic radio frame structure (‘frame Type 1’) and the TDD specific radio frame structure (‘frame Type 2’) is described in section 4.2. The E- radio frame structure (‘frame Type 2’) is described in section 4.2. The E- UTRA channel architecture, focusing on the physical channels and UTRA channel architecture, focusing on the physical channels and physical signals, is described in section 4.3. The associated layer 2 and physical signals, is described in section 4.3. The associated layer 2 and layer 3 protocol architecture is dealt with separately in chapter 5. The layer layer 3 protocol architecture is dealt with separately in chapter 5. The layer 1 processing chain for the uplink and downlink data channels is described 1 processing chain for the uplink and downlink data channels is described in section 4.4. Section 4.5 deals with the mapping of uplink and downlink in section 4.4. Section 4.5 deals with the mapping of uplink and downlink data and control channels onto 2-dimensional time-frequency radio data and control channels onto 2-dimensional time-frequency radio resources.

4.2 Radio Radio Frame Frame StructureStructure

4.2.1 Frame Frame Type Type 11

# #00 ##11 ##22 ##33 ##44 ##55 ##66 ##1188 ##1199 slot 0 slot 0 #7 #7 slot 19 slot 19 1 Radio Frame = 10ms 1 Radio Frame = 10ms 1 slot = 1 slot = 0.5ms 0.5ms 1 subframe = 1ms 1 subframe = 1ms # #00 ##11 ##22 ##33 ##44 ##55 ##66 ##1188 ##1199 slot 0 slot 0 #7 #7 slot 19 slot 19 1 Radio Frame = 10ms 1 Radio Frame = 10ms 1 slot = 1 slot = 0.5ms 0.5ms 1 subframe = 1ms 1 subframe = 1ms # #00 ##11 ##22 ##33 ##44 ##55 ##66 ##1188 ##1199 slot 0 slot 0 #7 #7 slot 19 slot 19 1 Radio Frame = 10ms 1 Radio Frame = 10ms 1 slot = 1 slot = 0.5ms 0.5ms 1 subframe = 1ms 1 subframe = 1ms

Figure 4-1: E-UTRA frame Type 1 Figure 4-1: E-UTRA frame Type 1

All bandwidth options have the same basic Transmission Time Interval All bandwidth options have the same basic Transmission Time Interval (TTI) of 1ms. As shown in figure 4-1,

(TTI) of 1ms. As shown in figure 4-1, the E-UTRA radio frames are 10 msthe E-UTRA radio frames are 10 ms in duration, divided into 10 sub-frames of 1ms duration. Thus, the in duration, divided into 10 sub-frames of 1ms duration. Thus, the subframe length coincides with the TTI. Each subframe is further divided subframe length coincides with the TTI. Each subframe is further divided into two slots, each of 0.5ms duration.

into two slots, each of 0.5ms duration.

As mentioned earlier, the downlink transmission scheme is based on As mentioned earlier, the downlink transmission scheme is based on conventional OFDM with cyclic prefix and the uplink transmission conventional OFDM with cyclic prefix and the uplink transmission scheme is based on SC-FDMA with cyclic prefix. Both downlink and scheme is based on SC-FDMA with cyclic prefix. Both downlink and uplink use the same cyclic prefix lengths and the same sub-carrier spacing uplink use the same cyclic prefix lengths and the same sub-carrier spacing of 15 kHz. In addition there is also a reduced sub-carrier spacing, 7.5 kHz, of 15 kHz. In addition there is also a reduced sub-carrier spacing, 7.5 kHz, for MBMS-dedicated cells. In the case of 15 kHz sub-carrier spacing there for MBMS-dedicated cells. In the case of 15 kHz sub-carrier spacing there are two cyclic prefix lengths, corresponding to 7 and 6 OFDM/SC-FDMA are two cyclic prefix lengths, corresponding to 7 and 6 OFDM/SC-FDMA symbols per slot respectively:

symbols per slot respectively:

•• Normal cyclic prefix: T Normalcyclic prefix: TCPCP = 160= 160××Ts (symbol #0) and TTs (symbol #0) and TCPCP = 144= 144××TsTs (symbol #1 to #6). The slightly longer CP in

(symbol #1 to #6). The slightly longer CP in the first symbol is inthe first symbol is in order to preserve the 0.5ms slot timing.

order to preserve the 0.5ms slot timing.

•• Extended cyclic prefix: T Extended cyclic prefix: TCP-eCP-e = 512= 512××Ts (all symbols). The Ts (all symbols). The extendedextended CP is intended for large cells, where larger delay spreads for

CP is intended for large cells, where larger delay spreads for multipath echoes are to be

multipath echoes are to be expected.expected. The parameter T

The parameter Tss above is called the ‘basic time unit’ and is defined asabove is called the ‘basic time unit’ and is defined as being T

being Tss = 1/ (2048= 1/ (2048 ×× ΔΔf) seconds, wheref) seconds, where ΔΔf is the sub-carrier spacing. Thef is the sub-carrier spacing. The length of T

length of Tss corresponds to the 30.72 MHz sample clock corresponds to the 30.72 MHz sample clock for the 2048-pointfor the 2048-point FFT used with the 20 MHz system bandwidth.

FFT used with the 20 MHz system bandwidth.

In case of 7.5 kHz sub-carrier spacing there is only a single cyclic prefix In case of 7.5 kHz sub-carrier spacing there is only a single cyclic prefix length, T

length, TCP-lowCP-low = 1024= 1024××Ts, corresponding to 3 OFDM symbols per slot.Ts, corresponding to 3 OFDM symbols per slot. The generic frame Type 1 can also be used for TDD operation in unpaired The generic frame Type 1 can also be used for TDD operation in unpaired spectrum. DL/UL switching points within the frame are then generated by spectrum. DL/UL switching points within the frame are then generated by not transmitting in certain symbols (creating a guard period between not transmitting in certain symbols (creating a guard period between uplink and downlink transmissions in different

uplink and downlink transmissions in different sub-frames).sub-frames). Apis Technical Training AB

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4.2.2 Frame Frame Type Type 22

# #00 ##11 ##22 ##33 ##44 ##55 ##66 ##55 ##66 D DLL UULL #0 #0 1 Radio Frame 1 Radio Frame 1 Half-frame = 5 ms 1 Half-frame = 5 ms

Downlink Pilot Timeslot

Guard Intervals Guard Intervals Guard Period

Guard Period Uplink Pilot Timeslot

Uplink Pilot Timeslot

1 Slot = 1 Slot = 1 Subframe 1 Subframe # #00 ##11 ##22 ##33 ##44 ##55 ##66 ##55 ##66 D DLL UULL #0 #0 1 Radio Frame 1 Radio Frame 1 Half-frame = 5 ms 1 Half-frame = 5 ms

Downlink Pilot Timeslot

Guard Intervals Guard Intervals Guard Period

Guard Period Uplink Pilot Timeslot

Uplink Pilot Timeslot

1 Slot = 1 Slot = 1 Subframe 1 Subframe # #00 ##11 ##22 ##33 ##44 ##55 ##66 ##55 ##66 D DLL UULL #0 #0 1 Radio Frame 1 Radio Frame 1 Half-frame = 5 ms 1 Half-frame = 5 ms

Downlink Pilot Timeslot

Guard Intervals Guard Intervals Guard Period

Guard Period Uplink Pilot Timeslot

Uplink Pilot Timeslot

1 Slot = 1 Slot = 1 Subframe 1 Subframe

Figure 4-2: E-UTRA frame Type 1 Figure 4-2: E-UTRA frame Type 1

Frame structure Type 2 is only applicable to TDD, with

Frame structure Type 2 is only applicable to TDD, with the sole purpose of the sole purpose of being backwards compatible with the 1.28Mcps TDD option in UMTS. being backwards compatible with the 1.28Mcps TDD option in UMTS. 1.28Mcps TDD is the Chinese 3G standard, also known as Low Chip-rate 1.28Mcps TDD is the Chinese 3G standard, also known as Low Chip-rate TDD (LCR-TDD) or Time Division Synchronous Code Division Multiple TDD (LCR-TDD) or Time Division Synchronous Code Division Multiple Access (TD-SCDMA).

Access (TD-SCDMA).

Each 10ms radio frame consists of two half-frames of length 5ms each. Each 10ms radio frame consists of two half-frames of length 5ms each. The structure of each half-frame in a radio frame is identical. Each half- The structure of each half-frame in a radio frame is identical. Each half- frame consists of seven slots and three special fields: the downlink pilot frame consists of seven slots and three special fields: the downlink pilot timeslot (DwPTS), the guard period (GP) and the uplink pilot timeslot timeslot (DwPTS), the guard period (GP) and the uplink pilot timeslot (UpPTS). A subframe is defined as one slot. This frame structure is (UpPTS). A subframe is defined as one slot. This frame structure is identical to the one used for TD-SCDMA.

identical to the one used for TD-SCDMA.

Subframe 0 and DwPTS are always reserved for downlink transmission Subframe 0 and DwPTS are always reserved for downlink transmission and UpPTS and subframe 1 are

and UpPTS and subframe 1 are always reserved for uplink transmission.always reserved for uplink transmission. For frame structure Type 2 the CP length in the downlink is T

For frame structure Type 2 the CP length in the downlink is TCPCP = 224= 224××TsTs (normal CP) and T

(normal CP) and TCP-eCP-e = 512= 512××Ts (extended CP) corresponding to 9 and 8Ts (extended CP) corresponding to 9 and 8 OFDM symbols per slot

OFDM symbols per slot respectively.respectively.

For the uplink the situation is slightly less straightforward when it comes For the uplink the situation is slightly less straightforward when it comes to CP lengths. There are several CP lengths used within each slot, to CP lengths. There are several CP lengths used within each slot, depending on the size of the allocated uplink resource and the index of the depending on the size of the allocated uplink resource and the index of the SC-FDMA symbol within a slot. The normal CP length is 192, 204, 224, SC-FDMA symbol within a slot. The normal CP length is 192, 204, 224, 320, 1024 and 2048

320, 1024 and 2048××Ts, corresponding to 9 SC-FDMA symbols. TheTs, corresponding to 9 SC-FDMA symbols. The extended CP length is 423, 456, 472, 560, 1024 and 2048

extended CP length is 423, 456, 472, 560, 1024 and 2048××Ts,Ts,

corresponding to 8 SC-FDMA symbols. corresponding to 8 SC-FDMA symbols.

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