Simultaneous usage of TV spectrum for mobile broadband and TV broadcast transmission. Joachim Sachs Ericsson Research AAchen, Germany

Transcription

1 Simultaneou uage of TV pectrum for mobile broadband and TV broadcat tranmiion Joachim Sach Ericon Reearch AAchen, Germany

2 OUtline Background and motivation Spectrum haring between TV and mobile network TV White Space (inter-weave) TV Black Space (overlay) Summary Joachim Sach ITG FG Workhop Ericon AB Page 2

3 OUtline Background and motivation Spectrum haring between TV and mobile network TV White Space (inter-weave) TV Black Space (overlay) Summary Joachim Sach ITG FG Workhop Ericon AB Page 3

4 Background Mobile Communication immene yearly traffic increae (~ %) tranition from cellular telephony to mobile broadband huge impact on national welfare and economic growth pectrum availability MHz Radio pectrum i the bai for mobile communication Joachim Sach ITG FG Workhop Ericon AB Page 4

5 Spectrum For Mobile Communication - Germany Spectrum auction May 2010 FDD DL FDD UL 360 MHz auctioned in May MHz Frequency band 1.8 GHz 2.0 GHz TDD FDD UL FDD UL TDD FDD DL FDD DL FDD UL / TDD TDD FDD DL / TDD 2.6 GHz Total pectrum increaed from 252 to 612 MHz in 2010 Fragmented pectrum allocation in multiple band Joachim Sach ITG FG Workhop Ericon AB Page 5

6 3GPP LTE Flexible Ue of Spectrum (1) Flexible bandwidth from MHz Paired (FDD) and unpaired (TDD) pectrum Joachim Sach ITG FG Workhop Ericon AB Page 6

7 3GPP LTE Flexible Ue of Spectrum (2) Carrier aggregation of multiple carrier different carrier bandwidth within ame pectrum band contiguou carrier non-contiguou acro different band Band A One component carrier Band A Band A Band B Joachim Sach ITG FG Workhop Ericon AB Page 7

8 Spectrum Requirement Yearly traffic growth of % 1000-fold traffic increae in 6-10 year ITU tudy (2006) on pectrum requirement for mobile communication Required pectrum in MHz Available a of May 2010 (Germany) 612 MHz Tremendou amount of additional pectrum i needed for mobile communication Joachim Sach ITG FG Workhop Ericon AB Page 8

9 pectrum in europe Joachim Sach ITG FG Workhop Ericon AB Page 10

10 pectrum in europe ~0 MHz unallocated! Joachim Sach ITG FG Workhop Ericon AB Page 11

11 pectrum in europe But not fully utilized Ericon Reearch meaurement in Kita Relative power [db] Frequency [MHz] Time [] Ericon Reearch White Space availability analyi Joachim Sach ITG FG Workhop Ericon AB Page 12

12 New Spectrum For Mobile Communication Re-allocation of pectrum from other indutrie internationally harmonized pectrum aignment global economy of cale uncertain if ufficient pectrum band can be found uncertain ucce of hotile lobbying / take-over Secondary uage of other pectrum invetigated a dynamic pectrum acce or cognitive radio ytem flexible uage of pectrum uncertain feaibility Joachim Sach ITG FG Workhop Ericon AB Page 13

13 Spectrum Sharing with TV Broadcat Sytem TV Broadcat large amount of pectrum (~377 MHz) ued not very efficiently good propagation characteritic imple and predictable open tandard, tatic uage, public info Joachim Sach ITG FG Workhop Ericon AB Page 14

14 OUtline Background and motivation Spectrum haring between TV and mobile network TV White Space (inter-weave) TV Black Space (overlay) Summary Joachim Sach ITG FG Workhop Ericon AB Page 15

15 Scenario: Spectrum Sharing TV frequency band Mobile frequency band Joachim Sach ITG FG Workhop Ericon AB Page 16

16 Scenario: Spectrum Sharing TV frequency band Opportunitic capacity extenion a econdary uer in TV band Mobile frequency band Joachim Sach ITG FG Workhop Ericon AB Page 17

17 Coexitence: Interference Channel Primary tranmitter T P Primary receiver R P Mutual Interference T S Secondary tranmitter R S Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 18

18 Coexitence: Interweave Spectrum Sharing (1) Separate primary and econdary tranmiion in ignal domain time, frequency pace Primary tranmitter Primary receiver T P X R P Orthogonalize ignal T S Secondary tranmitter X R S Secondary receiver White Space for econdary uage Primary protection zone Primary ervice area Joachim Sach ITG FG Workhop Ericon AB Page 20

19 Regulatory Situation Regulator FCC ha allowed econdary uage of TV pectrum (Nov. 2008, Sep. 2010) CEPT SE 43 report on econdary uage of TV pectrum (Sept. 2010) Approach regulated databae for availability of regionally ueable TV channel geo-location can be determined for econdary tranmitter protection of TV reception within ervice area Spectrum databae Joachim Sach ITG FG Workhop Ericon AB Page 21

20 concluion TV White SPace Technical approach i imple mobile network could eaily be adapted to TV white pace uage Conervative protection rule ignificant amount of unued pectrum not ueable reduce amount of white pace pectrum More TV white pace pectrum available in area with lower population denitie mimatch of capacity and demand Joachim Sach ITG FG Workhop Ericon AB Page 22

21 Coexitence: Overlay Spectrum Sharing (1) Simultaneou tranmiion in time, frequency, pace TV black pace Baed on cooperative tranmiion cognitive of primary ytem ignal (non caual) cooperative in ignal deign Primary tranmitter T P Primary receiver R P Black Space for econdary uage cognition Primary ervice area T S Secondary tranmitter R S Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 23

22 Coexitence: Overlay Spectrum Sharing (2) Primary ytem protection Relay (amplify) primary ignal with power fraction α Superpoition coding of primary and econdary ignal Primary tranmitter T P cognition α P T S Secondary tranmitter h PS h SP Primary receiver Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 24 R P Amplify ignal R S SNR p = = h h p N p p N 2 p P P p p + h p + (1 α) h α P (1-α) fraction of power for 2-dary tx. P S, P S primary econdary tx. power channel gain h x p 2 P 2

23 Coexitence: Overlay Spectrum Sharing (3) Secondary tranmiion Cancel primary-to-econdary interference Primary tranmitter Primary receiver T P cognition h PS R P SNR = N + (1 α) h h p 2 P p + 2 h P 2 α P ( 1 α)p T S Secondary tranmitter Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 25 h S R S (1-α) fraction of power for 2-dary tx. P S, P S primary econdary tx. power channel gain h x

24 Coexitence: Overlay Spectrum Sharing (4) Secondary tranmiion Cancel primary-to-econdary interference Tranmitter: Dirty Paper Coding Primary tranmitter Primary receiver T P cognition h PS R P SNR = N + (1 α) h h p 2 P p + 2 h P 2 α P T S Secondary tranmitter X X Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 26 h S R S Code againt known interference (1 α) h = N 2 P (1-α) fraction of power for 2-dary tx. P S, P S primary econdary tx. power channel gain h x

25 Coexitence: Overlay Spectrum Sharing (5) Secondary tranmiion Cancel primary-to-econdary interference Tranmitter: Dirty Paper Coding Receiver: Interference Cancellation Primary tranmitter Primary receiver T P cognition h PS R P SNR = N + (1 α) h h p 2 P p + 2 h P 2 α P T S Secondary tranmitter Secondary receiver Joachim Sach ITG FG Workhop Ericon AB Page 27 h S X X R S Cancel interference (1 α) h = N 2 P (1-α) fraction of power for 2-dary tx. P S, P S primary econdary tx. power channel gain h x

26 Coexitence: Overlay Spectrum Sharing (6) Information theory [Devroye, Mitran, Tarokh. Tran. IT 2006] [Maric, Yate, Kramer, Tran. IT 2007] [Wu, Vihwanath, Arapotathi, Tran. IT 2007 ] [Jovicic, Viwanath, Tran. IT, 2009 ] [Maric, Goldmith, Kramer, Shamai, ETT 2008] [Jiang, Xin, Tran. IT 2008] Sytem analyi [Sach, Maric, Goldmith. DySPAN 2010] Primary tranmitter T P Primary receiver R P Cognitive Radio Channel cognition Joachim Sach ITG FG Workhop Ericon AB Page 28 T S Secondary tranmitter R S Secondary receiver

27 Realization: Overlay Spectrum Sharing Cognition baed on ome genie non-caual knowledge of primary ignal Primary tranmitter Primary receiver T P R P cognition T S Secondary tranmitter R S Secondary receiver How can thi be achieved? Joachim Sach ITG FG Workhop Ericon AB Page 29

28 Digital TV Network DTV encoder DTV Ditribution Network Ditribution Network to TV tranmitter Single Frequency Network (SFN) operation upported in OFDM baed DTV ytem (e.g. DVB-T) ynchronized tranmiion from multiple TV tranmitter Joachim Sach ITG FG Workhop Ericon AB Page 30

29 Cellular TV Overlay: Network Deign DTV encoder DTV Ditribution Network TV codeword + timing Re-ue of DTV SFN tranmiion Cellular bae tation a TV SFN tranmitter Cellular Core Network TV band tranmiion mgmt. Joachim Sach ITG FG Workhop Ericon AB Page 31

30 Sytem Evaluation Approach One cellular radio cell and one TV tranmitter Idealized TV parameter Diplacement by ditance D Pathlo (COST 231 Hata) without hadowing h 2 = 1 c r e Downlink h p (d) h (d-d) h p (~0) maximum TV ervice range (R max ) h (D) ditance d Diplacement D Joachim Sach ITG FG Workhop Ericon AB Page 36

31 Sytem Evaluation TV RElay Power Secondary power level (alpha) required for TV relaying Relaying Power (alpha) Fraction of Power (alpha) for Relaying alpha alpha (no SNR lo) max. alpha Range A Range B Range C Range D A B C D E In different TV ervice area region Different power level for relaying In larget area 93% of power needed to protect TV reception Diplacement of Secondary Tranmitter D [m] Joachim Sach ITG FG Workhop Ericon AB Page 37

32 Sytem Evaluation Cellular Downlink Performance Power lo due to relaying Performance Lo of Cognitive Cellular Capacity compared to tandalone ytem 0 SINR lo of Cognitive Cellular Sytem [db] Range A Range B Range C Range D Power lo [1-alpha] TV relaying conume up to 93% of BS power Up to 11.5 db lo in link budget Propagation path more than 10dB lower Lo of relaying compenated by better propagation Ditance / Diplacement from TV tranmitter [m] Joachim Sach ITG FG Workhop Ericon AB Page 38

33 Concluion TV Black Space Cognitive cellular ytem in TV pectrum cooperation between TV and cellular operator cooperative relaying of TV ignal imultaneou cellular tranmiion Simultaneou TV+cellular tranmiion eem feaible Secured TV ervice performance Solid cellular performance in downlink Limited ue for cellular uplink More capacity i provided in dener populated area Joachim Sach ITG FG Workhop Ericon AB Page 39

34 OUtline Background and motivation Spectrum haring between TV and mobile network TV White Space (inter-weave) TV Black Space (overlay) Summary Joachim Sach ITG FG Workhop Ericon AB Page 40

35 Summary In future more pectrum for mobile broadband i required econdary pectrum uage may be an option Poibility pectrum haring with TV broadcat TV White Space (inter-weave) technically imple, regulation on it way regional traffic capacity mimatch TV Black Space (overlay) collaboration between TV and cellular network technically complex (downlink only) available where white pace i not Spectrum allocation take long time reearch i required now Joachim Sach ITG FG Workhop Ericon AB Page 41

36 Joachim Sach ITG FG Workhop Ericon AB Page 42