Sheng lung cheng department of communication engineering national chiao tung university 2011 10 17
Download
1 / 24

The Study Report of LTE Physical Layer Documents - PowerPoint PPT Presentation


  • 103 Views
  • Uploaded on

Sheng-Lung Cheng Department of Communication Engineering National Chiao Tung University 2011-10-17. The Study Report of LTE Physical Layer Documents. Outline. Introduction References DL/UL transmission train Discussible topics. Introduction.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' The Study Report of LTE Physical Layer Documents ' - ganya


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Sheng lung cheng department of communication engineering national chiao tung university 2011 10 17

Sheng-Lung Cheng

Department of Communication Engineering

National Chiao Tung University

2011-10-17

The Study Report of LTE Physical Layer Documents


Outline
Outline

  • Introduction

  • References

  • DL/UL transmission train

  • Discussible topics


Introduction

  • The goal of LTE is to provide a high-data-rate, low-latency

    and packet-optimized radioaccesstechnology supporting

    flexible bandwidthdeployments.

  • LTE system attributes


Reference

  • Farooq Khan ,“LTE for 4G Mobile Broadband: Air Interface Technologies and Performance References”, Cambridge , 2009-04-19.

  • Erik Dahlman, Stefan Parkvall, Johan Skold ,“4G: LTE/LTE-Advanced for Mobile Broadband”, Academic Press , 2011-05-09.

  • 3GPP TS 36.211: "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation".

  • van de Beek, J.J.; Sandell, M.; Borjesson, P.O.” ML estimation of time and frequency offset in OFDM systems ”, IEEE Transactions Signal Processing, 1800 – 1805, Jul 1997.


DL/UL system model

  • Frame structure(type1 for FDD and half-duplex FDD)



By applying different scrambling sequences for neighboring cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

DL/UL system model

  • Overview of downlink physical channel processing.


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Overview of uplink physical channel processing.


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink layer mapping

(A)

(B)


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink layer mapping

(C)


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink layer mapping

The rank assignment refers to RI


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink precoding

(A)

(B)

(1)


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

The precode matrix assignment refers to

PMI

  • Downlink precoding


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink precoding

Here the W(i) is not selected by UE.

(2)


DL/UL system model cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Downlink precoding

(C)

Precoding for transmit diversity

Antenna Port

Freq. Band


Antenna Port cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

Freq. Band

DL/UL system model

  • Downlink precoding


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Initial cell search


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Initial cell search


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Initial cell search

??

OFDM symbol timing synchronization

FD PSS

Radio frame timing synchronization

Cell ID determination

FD PSS and SSS

a. Using TD PSS

The length 62 FD Zadoff–Chu (ZC) sequence has bad TD performance when IFFT size is large.


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Initial cell search

a. Using CP


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • Initial cell search

Downlink CRS in one antenna transmission

Some OFDM symbols may not have any data, so the observation interval would be very large.


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • DCI (Downlink Control Information) blind detection

Downlink control information , DCI, provides the terminal with the necessary information for proper reception and decoding of the downlink data transmission.

Puncturing or repetition

Control-Channel Elements (CCEs), is a convenient name for a set of 36 useful resource elements. The number of CCEs, 1, 2, 4, or 8, required for a certain PDCCH depends on the DCI payload channel-coding rate.


Discussible topics cells, the interfering signal after descrambling is randomized, ensuring full utilization of the processing gain provided by the channel code.

  • DCI blind detection

As the number of CCEs for each of the PDCCHs may vary and is not signaled, the terminal has to blindly determine the number of CCEs used for the PDCCH it is addressed upon.

In release 8/9, the number of blind decoding attempts is 44 per subframe, while for release 10 with uplink spatial multiplexing the number is 60.


ad