System Architecture

2018 Fall Intro LTE

Chap6:LTE Air Interface

Tomohisa Wada

Information Engineering

1

Air Interface Protocol Stack

2

IP: Internet protocol

RRC: Radio Resource Control protocol

PDCP: Packet Data Convergence protocol

RLC: Radio Link Control protocol

MAC: Media Access Control protocol

Transport Channel Processor

-> Error management

Physical Channel Processor

-> OFDMA, SC-FDMA, MIMO

Analogue Processor

-> analog conversion, real wave

Logical Channels

3

<- connection related

<- Broadcast Master

Information Block (MIB),

System Information Block (SIB)

DTCH and DCCH are major Channels

Transport Channel

4

UL-SCH and DL-SCH are major Channels

<- PCCH<- MIB

<- + SIB

<- Multimedia Broadcasting Service

<- Initial Connection Request

Physical Data Channel

5

Control Information

6

Transport Channel Processor composes several types of control information

to support low-level operation of physical layer as shown in Table 6.4.

Physical Control Channel

7

Physical Signal

8

LTE Uplink Information Flows

9

LTE Downlink

Information Flows

10

FDD Frame

11

1 frame = 10 ms = 10 sub-frame

1 sub-frame = two slots

1 slot = 500 us = 0.5 ms = 7 OFDM symbols or 6 OFDM symbols

500 us

1slot

TDD Frame

12

1st and 5th sub-frame is always DL

Guard period

Resource Block

13

Resource block is minimum unit for one user.

1slot (0.5 ms) X 180KHz (12 sub-carriers)

<- QPSK(2bit), 16QAM(4bit), 64QAM(6bit)

Bandwidth Options

14

MIMO DL modes

15

DL FDD Frame Structure

Example

16

3MHz 15 Resource Blocks

Normal CP : 5 OFDM in one slot

1st antenna port of two

Not used x will be RS of 2nd antenna port

UL FDD Frame Structure

Example

17