電子航法研究所研究発表会（第14回平成 26年6月）

̔ɽσʔλϦϯΫ LDACS1 ͷϏοτ‫ޡ‬Γ཰ಛੑ‫ࢹ؂‬௨৴ྖҬ1.

˞๺ંɹ५ɺԘ‫֨ ݟ‬Ұɺॅ୩ɹହਓɺੴग़ɹ໌͸͡Ίʹࠃࡍຽؒߤۭ‫ؔػ‬͸ɺকདྷͷߤۭ௨৴धཁͷ૿େʹඋ͑ΔͨΊɺߴ଎σʔλϦϯΫγεςϜͷٕज़త‫ݕ‬౼ΛԤถ‫ڞ‬ಉ࡞‫ ۀ‬FCSʢFuture Com-munication StudyʣʹҕͶͨɻFCS ࠷ऴใࠂͰ͸ɺ৽ͨͳσʔλ௨৴γεςϜ͕ඞཁͰ͋Δͱͷ‫ݟ‬ղΛ͓ࣔͯ͠Γɺ·ͨ༸্௨৴ɺରۭ௨৴ɺਤ 1 LDACS1 εʔύϑϨʔϜߏ੒ [2]ۭߓ໘௨৴ͱɺ௨৴༻్ʹԠͯ͡ద੾ͳߤۭ௨৴γεςϜΛબ୒͠࢖༻͢Δ͜ͱΛਪ঑͍ͯ͠
Δɻରۭ௨৴ʹ͓͍ͯ͸ɺVHF ଳͰ༻͍ΒΕ
͍ͯΔ‫ߦݱ‬ͷ VDLʢVHF Digital LinkʣMode2΍ ACARSʢAircraft Communications Addressing

and Reporting Systemʣʹ୅ΘΔσʔλ௨৴γεςϜީิͱͯ͠ɺL όϯυʹ͓͚Δߴ଎σʔλϦϯΫ LDACSʢL-band Digital AeronauticalCommunications SystemʣΛఏҊ͍ͯ͠Δ [1]ɻ͔͠͠‫Ͱ·ࡏݱ‬ͷͱ͜ΖɺLDACS ͷ‫ࣗ֨ن‬ମ͕LDACS1[2] ͱ LDACS2[3] ͱ͍͏ 2 छྨͷ‫֨ن‬Ҋ͕ฒཱ͍ͯ͠Δஈ֊ʹཹ·͓ͬͯΓɺLDACSͷຊ֨తͳ‫֨ن‬Խʹ͸·͕͔͔ͩ࣌ؒΔ΋ͷͱਤ 2 ύΠϩοτ৴߸഑ஔྫ

ߟ͑ΒΕ͍ͯΔɻ͜Ε·Ͱʹిࢠߤ๏‫Ͱॴڀݚ‬͸ɺLDACS ෺ཧ૚࣮‫ݧ‬γεςϜΛ࡞੒͠ [4]ɺҰ෦ͷੑೳʹ͍ͭͯ‫[ ͖ͨͯ͠ূݕ‬5, 6]ɻຊใࠂͰ͸ LDACS1 ʹ͍ͭͯ‫ج‬ຊతͳ௨৴ੑೳࢦඪͰ͋Δ BERʢBitError Rate; Ϗοτ‫ޡ‬Γ཰ʣಛੑͷධՁ݁Ռʹ͍ͭͯใࠂ͢Δɻ2.

LDACS1 ͷૹ৴ϑΥʔϚοτΛਤ 1 ʹࣔ͢ɻ௕͞ 240 ms ͷεʔύϑϨʔϜΛ‫ج‬ຊ୯Ґͱͯ͠ɺ͞Βʹࡉ͔͍୯ҐͷϑϨʔϜʹ෼ׂ͍ͯ͠
Δɻ·ͨ FL ͱ RL ͱͰ͸ҟͳΔϑϨʔϜϑΥʔLDACS1 ֓ཁϚοτΛ༻͍Δɻೋ࣍มௐͰ͸ 50 ຊͷαϒΩϟLDACS1 ͸ VDL Mode2 ౳ͱҟͳΓ஍্‫→ ہ‬

ϦΞΛ FFTʢFast Fourier TransformɺαΠζ 64ʣߤۭ‫޲ํہػ‬ͷ FLʢForward Linkʣͱߤۭ‫ہػ‬Ͱ࣌ؒ৴߸ʹม‫͢׵‬Δɻ͞ΒʹɺRL Ͱ͸ 50 ຊ→ ஍্‫޲ํہ‬ͷ RLʢReverse LinkʣͱͰผʑͷप೾਺νϟωϧΛׂΓ౰ͯΔɻFL ͸஍্‫͔ہ‬Β OFDMʢOrthogonal Frequency Division Multiplexʣ৴߸Λ࿈ଓૹ৴͠ɺ֤ߤۭ‫ʹہػ‬ରͯ͠‫ݸ‬ͷαϒΩϟϦΞΛ௿͍प೾਺ͷ 25 ຊͱߴ͍प೾਺ͷ 25 ຊͷ 2 ͭʹ෼͚ɺผʑͷϢʔβʹ࢖༻͢Δɻ·ͨɺOFDM Ͱνϟωϧਪఆʹ࢖༻͢ΔύΠϩοτ৴߸ͷ഑ஔ΋ϑϨʔϜͷ‫ʹܕ‬Ԡܾͯ͡ผࢦఆ·ͨ͸ಉ࣌௨ใͷ఻ૹ͕ߦ͑Δνϟωϧ

ΊΒΕ͍ͯΔɻྫͱͯ͠ɺਤ 2 ʹϢʔβσʔλͰ͋ΔɻҰํɺRL ͸஍্‫͔ہ‬Βͷཁ‫ʹٻ‬Ԡͯ͡఻ૹʹ༻͍Δ FL σʔλϑϨʔϜͱ RL σʔλϑׂΓ౰ͯΒΕͨߤۭ‫͕ہػ‬όʔετঢ়ʹૹ৴͢ϨʔϜͷύΠϩοτ৴߸഑ஔΛࣔ͢ɻ

Δ OFDMA-TDMAʢOrthogonal Frequency Division Multiple ɹ Access–Time Division MultipleAccessʣํࣜͷνϟωϧͰ͋Δɻʮ‫ޡ‬Γగਖ਼‫ޙ‬ͷ BER ͕ 10−6 ʯͱ‫ن‬ఆ͞Ε͍ͯΔͳ͓ɺड৴ੑೳධՁʹ࢖ΘΕΔࢀর BER ஋͸[2]ɻLDACS1 ͷओཁॾ‫ݩ‬Λද 1 ʹࣔ͢ɻ－ 41 －電子航法研究所研究発表会（第14回平成 26年6月）

LDACS1 ओཁॾ‫ݩ‬࢖༻प೾਺ଳෳ৴ํࣜΞΫηεํࣜมௐํࣜνϟωϧ෯Ϗοτ఻ૹ଎౓֎ූ߸‫ޡ‬Γగਖ਼಺ූ߸FFT αΠζαϯϓϦϯά࣌ؒ
OFDM γϯϘϧ௕αϒΩϟϦΞ਺αϒΩϟϦΞִؒLDACS1 BER performances in FL Data frame, under AWGN channel
100

960—1164[MHz]QPSK+FECQPSK
16QAM+FEC
16QAM
64QAM+FEC
64QAM

10-1

प೾਺෼ׂ
10-2

OFDMA
4/16/64QAM+OFDM
498.05[kHz] x 2
833.33—2500.0[kbps]

Bit Error Rate

ද110-310-410-5ϦʔυιϩϞϯʢύϯΫνϟυʣ৞ΈࠐΈ

10-6

64
1.6[µs]120[µs]509.765625[kHz]10-724ਤ4681012141618
C/N [dB]

202224262830FL σʔλϑϨʔϜมௐํࣜผ BER ಛੑఆٛ͞Ε͍ͯΔɻϑΣʔδϯάͷͳ͍੩త௨৴‫ڥ؀‬ԼͰͷมௐํࣜผ FL σʔλϑϨʔϜ BERಛੑΛਤ 4 ʹࣔ͢ɻ‫ޡ‬Γగਖ਼લ BER ͸ཧ࿦্ͷಛੑʹൺ΂͍ͣΕ΋ྼԽ͕‫ݟ‬ΒΕΔ͕ɺ4QAM͸ྼԽ౓߹͍͕গͳ͘ྑ޷ͳಛੑͰ͋ͬͨɻ·ͨ‫ޡ‬Γగਖ਼લ BER ͕ 10−2 ʙ10−1 ఔ౓ҎԼͰగਖ਼ූ߸͕ޮ͖ɺ4QAM Ͱ C/N = 8 [dB]ɺ64QAMͰ΋ C/N = 14 [dB] Ͱ‫ޡ‬Γగਖ਼‫ޙ‬ͷ BER ͕ 0 ͱͳͬͨɻ
ਤ 3 ࣮‫ߏݧ‬੒ਤ

4.23.

प೾਺γϑτ଱ੑυοϓϥγϑτʹ୅ද͞ΕΔΑ͏ʹɺड৴৴߸࣮‫ํݧ‬๏

LDACS ෺ཧ૚࣮‫ݧ‬γεςϜ͸ɺPC ͱ৴߸ૹड৴ϑϩϯτΤϯυ USRPʢUniversal SoftwareRadio PeripheralʣͰߏ੒͞ΕΔ [4]ɻPC ্Ͱ৴߸ॲཧϥΠϒϥϦ GNURadio[7] Λ༻͍ͨ LDACS෺ཧ૚ಈ࡞ϓϩάϥϜ౳Λ૸Β࣮ͤͯ‫ݧ‬ΛߦͬͨɻຊߘͰ͸ɺਤ 3 ʹࣔ͢Α͏ʹɺૹ৴৴߸͸೚ҙ೾‫ൃܗ‬ੜ‫Ͱث‬ϓϦΞϯϒϧΛ෇Ճͨ͠ϑϨʔϜΛ‫܁‬Γฦ͠ൃੜͤ͞ɺड৴ଆͷ PC Ͱ‫ޡ‬Γగਖ਼લ‫ޙ‬ͷ BER Λଌఆͨ͠ɻͳ͓ɺຊߘͰ͸ LDACS1ͷ֤छϑϨʔϜͷ͏ͪ FL σʔλϑϨʔϜʢ௕͞ 52 OFDM γϯϘϧʣ‫ ͼٴ‬RL σʔλϑϨʔϜ
ʢ௕͞ 6 OFDM γϯϘϧʣΛର৅ͱͨ͠ɻ

ʹप೾਺γϑτ͕ൃੜ͢Δ͜ͱ͕͋Δɻ৴߸ൖૹ೾प೾਺ʹप೾਺γϑτΛൃੜͤ͞ड৴ͤ͞
ͨ৔߹ͷ BER ಛੑΛਤ 5 ʹࣔ͢ɻFL Ͱ͸प೾਺γϑτ͕ ±1.5 kHz Ͱ΋‫ޡ‬Γగਖ਼‫ ޙ‬BER= 0 Ͱ͋ͬͨɻ͜Ε͸ൖૹ೾प೾਺ 970 MHz ͷ৔߹໿
1670 km/hʢ900 ϊοτʣͷҠಈ଎౓ʹ૬౰͢ΔɻҰํ RL Ͱ͸γϑτ͕ ±300 Hz ఔ౓Ͱ‫ޡ‬Γగਖ਼‫ ޙ‬BER> 10−6 ͱͳͬͨɻ4.3ϑΣʔδϯά‫ڥ؀‬ߤۭ‫ػ‬ͷҠಈʹ൐͍ϚϧνύεϑΣʔδϯά͕ൃੜ͢Δɻจ‫[ ݙ‬2]App.A ʹ͋Δ୅දతͳ௨৴νϟωϧϞσϧྫΛࢀߟʹͯ͠ɺϑΣʔδϯά‫؀‬‫ڥ‬Λද 2 ͷΑ͏ʹఆΊ BER ಛੑΛଌఆͨ͠ɻਤ

4. BER ಛੑ࣮‫݁ݧ‬Ռ
4.1 ੩త௨৴‫ڥ؀‬LDACS1 ͷ Ұ ࣍ ม ௐ ͸ QPSKʢQuadraturePhase Shift Keyingʣ=4QAMʢQuadrature Amplitude Modulationʣɺ16QAMɺ64QAM ͷ 3 छྨ͕

6 ʹ ENR ‫ڥ؀‬ɺਤ 7 ʹ TM ‫ڥ؀‬ɺਤ 8 ʹ APT ‫؀‬‫͚͓ʹڥ‬Δ BER ಛੑΛࣔ͢ɻFL ͸ ENRɺTMͰࢀর BER ஋ʹରԠ͢Δ C/N ͕ͦΕͧΕ 9 dBɺ
15 dB ͱͳ͕ͬͨɺAPT Ͱ͸ࢀর BER ஋ʹରԠ
͢Δ C/N ͸ಘΒΕͳ͔ͬͨɻ·ͨɺRL ʹ͍ͭ－ 42 －

電子航法研究所研究発表会（第14回平成 26年6月）

ද2ϑΣʔδϯά‫ڥ؀‬ઃఆϑΣʔδϯάλΠϓ
஗Ԇ [µs]ϐϡΞυοϓϥ0ϨΠϦʔ0.3ϨΠϦʔ15ϥΠεʢK = 10[dB]ʣ0ϨΠϦʔ0‫໊ڥ؀‬ENRʢΤϯϧʔτʣTMʢλʔϛφϧʣ
APTʢۭߓ໘ʣ‫ݮ‬ਰ [dB]࠷େυοϓϥγϑτ [Hz]0162200997
603-594498330

BER performance vs frequency shift

LDACS1 BER performances (TM)

100

100

10-1

10-1

10-2

FL+FECFL
RL+FECRL

10-3

Bit Error Rate

BER CNR=20[dB]

10-2

10-4

10-3

10-4

10-510-510-610-610-7-1500-1200-900-600-300

0300

600

900

1200

10-71500

FL+FECFL
RL+FEC
RL024681012Frequency shift [Hz]182022242628302830

ਤ 7 TM ‫ ڥ؀‬BER ಛੑLDACS1 BER performances (ENR)LDACS1 BER performances (APT)

10010010-110-110-210-2

Bit Error Rate

Bit Error Rate

16C/N [dB]

ਤ 5 प೾਺γϑτ଱ੑ

10-310-410-510-310-4

10-510-610-7

1410-6

FL+FECFL
RL+FEC
RL
024ਤ66810C/N [dB]

1214161810-720ENR ‫ ڥ؀‬BER ಛੑ

FL+FECFL
RL+FEC
RL
0246810121416C/N [dB]

1820222426

ਤ 8 APT ‫ ڥ؀‬BER ಛੑͯ͸͍ͣΕ΋ࢀর BER ஋ʹରԠ͢Δ C/N ͸ಘʢDecision Feedback EqualizerʣΞϧΰϦζϜΛΒΕͳ͔ͬͨɻ࣮૷͍͕ͯͨ͠ɺFL ͱ RL ͱͰಛੑ͕େ͖͘ҟ4.4ͳͬͨɻ͜Ε͸ɺਤ 2 ͔ΒΘ͔ΔΑ͏ʹ FL ͸ߟ࡯ຖ OFDM γϯϘϧʹύΠϩοτ৴߸͕഑ஔ͞Εप೾਺γϑτ଱ੑ΍ϑΣʔδϯά‫ڥ؀‬ԼͰͷ͍ͯΔͷʹରͯ͠ɺRL ͸ύΠϩοτ৴߸ͷ࣌ؒ

BER ಛੑ͸ಛʹ RL ͰͷྼԽ͕‫ݦ‬ஶͰ͋ͬͨɻ
4.2 અͷप೾਺γϑτ଱ੑͰ͸ɺFL ͸ ±1.5 kHz·Ͱे෼ͳ଱ੑ͕͋ͬͨͷʹରͯ͠ɺRL ͸ ±300Hz ͷγϑτͭ·Γ଎౓໿ 334 km/hʢ180 ϊοτʣͰ΋ड৴ BER ‫ج‬४Λ௒͑ͨɻࠓճύΠϩοτ৴߸Λར༻ͨ͠౳Խॲཧͱͯ͠ɺҰൠతͳ DFEత഑ஔ͕ඈͼඈͼͰ͋ΔͨΊʹɺຖ OFDM γϯϘϧͰͷ౳Խॲཧͱ͸ͳΒͣɺద੾ͳνϟωϧਪఆ͕ߦ͑ͳ͔ͬͨ΋ͷͱߟ͑ΒΕΔɻͦ͜Ͱɺ

RL ͷύΠϩοτ৴߸഑ஔʹదͨ͠಺ૠ౳ԽΞϧΰϦζϜͰಉ༷ͷप೾਺γϑτ଱ੑΛ‫ٻ‬ΊͯΈͨͱ͜Ζɺਤ 9 ͷΑ͏ʹ ±700 Hz ఔ౓·Ͱ଱ੑ－ 43 －

電子航法研究所研究発表会（第14回平成 26年6月）

FL ͱ RL ͱͰେ͖͘ҟͳΔ͜ͱ͕Θ͔ͬͨɻಉ

BER performance vs frequency shift100Ұͷ౳ԽΞϧΰϦζϜΛ༻͍ͨ৔߹Ͱͷಛੑ͕
10-1

BER CNR=20[dB]ҟͳΔ͜ͱ͔ΒɺύΠϩοτ৴߸഑ஔ͕Ө‫ͯ͠ڹ‬

RL+FEC (interpolation)
RL (interpolation)

10-2͍Δͱ‫͑ݴ‬Δɻͭ·ΓɺFL ͱ RL ͱͰͦΕͧΕద੾ͳ BER ಛੑΛಘΔͨΊʹ͸‫ݸ‬ผʹ౳ԽΞϧ

10-3ΰϦζϜΛ‫ݕ‬౼͍ͯ͘͠ඞཁ͕͋Δɻ

-4

105.

10-5

10-7-1500·ͱΊ

LDACS1 Ͱ͸ FL ͱ RL ͱͰϑϨʔϜߏ੒‫ٴ‬

10-6-1200-900-600-300
0300
Frequency shift [Hz]6009001200ͼύΠϩοτ৴߸഑ஔ͕ҟͳΓɺಉҰͷ౳ԽΞϧ1500

ΰϦζϜͰ͸े෼ͳ BER ಛੑ͸ಘΒΕͳ͍͜ͱਤ 9 प೾਺γϑτ଱ੑʢ಺ૠ౳Խʣ͕Θ͔ͬͨɻ·ͨϨΠϦʔϑΣʔδϯά‫Ͱڥ؀‬͸े෼ͳ‫ޡ‬Γగਖ਼͕ߦΘΕͣɺσʔλͷ࠶ૹ͕ස͕վળ͞Εͨɻͳ͓ɺLDACS1 ड৴‫ػ‬ͷड৴‫ײ‬౓ఆٛͰ͸Ҡಈ଎౓ 850 ϊοτʹ૬౰͢Δप೾਺γϑτ࣌ʹ΋ରԠ͢Δ͜ͱ͕‫ٻ‬ΊΒΕ͓ͯΓ

[2]ɺRL ʹ͍ͭͯ͸͞ΒͳΔվળ͕ඞཁͱߟ͑ΒΕΔɻਤ 6ɺਤ 7ɺਤ 8 ͷ֤ϑΣʔδϯά‫ڥ؀‬ԼͷBER ಛੑͰ΋ɺ౳Խॲཧ͸લड़ͷ DFE ΞϧΰϦζϜͰߦͬͨɻFL Ͱ͸ APT ͷΑ͏ͳϨΠϦʔϑΣʔδϯά‫Ͱڥ؀‬͸ C/N ͕ߴͯ͘΋ BER ͕େ͖͘ɺϓϩτίϧ্Ґ૚Ͱͷ࠶ૹ‫ߏػ‬౳ʹΑΔσʔλิঈΛซ༻͢Δඞཁ͕͋ΔɻҰํͰɺ

ENR ΍ TM ͷΑ͏ͳ‫͍ڧ‬௚઀೾Λड͚ΒΕΔ‫؀‬‫Ͱڥ‬͸ߴ͍ C/N Ͱ͸‫ޡ‬Γగਖ਼͕ޮ͖ɺBER Λ཈͑Δ͜ͱ͕Ͱ͖ͨɻ͔͠͠ɺRL Ͱ͸ 3 छྨͷ‫؀‬‫ڥ‬ͷ࠷ྑ஋Ͱ΋‫ޡ‬Γగਖ਼‫ ޙ‬BER ͕ 0.08 ఔ౓Ҏ্͋ͬͨͨΊɺ͜ͷঢ়ଶͰ͸࠶ૹ͕සൟʹൃੜ͠σʔλ఻ૹʹෆదͰ͋ΔɻRL ʹ͍ͭͯ͸౳ԽΞϧΰϦζϜΛ಺ૠ౳Խʹมߋͨ͠ͱ͜ΖɺENRʹ͍ͭͯ͸ C/N = 30 [dB] Ͱ‫ޡ‬Γగਖ਼‫ ޙ‬BER ͕0.3 ఔ౓ͱґવߴ͔ͬͨɻENR ͸௚઀೾ͱ 2 ஗Ԇ೾ͷ߹੒͞ΕͨΤϯϧʔτඈߦதͷ௨৴Λ૝ఆͨ͠఻ൖϞσϧͰ͋Δ͕ɺ࠷΋৴߸ৼ෯͕େ͖͍௚઀೾ͷυοϓϥγϑτ͕໿ 1 kHz ͱେ͖͘લड़ͷप೾਺γϑτ଱ੑͷൣғΛ௒͍͑ͯΔͨΊ C/N ʹΑΒͣ BER ͕ྼԽͨ͠΋ͷͱߟ͑ΒΕΔɻ·ͨ APT ͱ TM Ͱ͸಺ૠ౳ԽΞϧΰϦζϜʹΑͬͯ BER ಛੑͷվળ͸‫ݟ‬ΒΕ͕ͨɺ͍ͣΕ΋ FL ͷ݁ՌΑΓѱ͔ͬͨɻಛʹ APT ͷΑ͏ͳϨΠϦʔϑΣʔδϯά‫Ͱڥ؀‬͸σʔλͷ࠶ૹ͕සൃ͢ΔՄೳੑ͕͋ΔɻҎ্ͷ݁ՌΑΓɺLDACS1 ͷ BER ಛੑ౳͸

ൃ͢ΔՄೳੑ͕͋Δɻࠓ‫ޙ‬͸ FL ͱ RL ʹͦΕͧΕదͨ͠౳ԽΞϧΰϦζϜΛ‫ٻ‬ΊɺධՁ͍ͯ͘͠༧ఆͰ͋Δɻ·ͨɺ౳ԽҎ֎ʹ΋৴߸ಉ‫ظ‬౳ͷॲཧ͕ड৴ੑೳΛࠨӈ͢Δ͜ͱ͔Βɺ͜ΕΒʹ͍ͭͯ΋‫͍ͯ͘͠ূݕ‬༧ఆͰ͋Δɻࢀߟจ‫ݙ‬[1] Nicolaos Fistas, Brent Phillips, and James
Budinger. Future communications study —action plan 17, ﬁnal conclusions and recommendations report. In 26th DASC, pp. 1–14. ,4.B.6, IEEE, Oct 2007.
[2] EUROCONTROL. Updated LDACS1 System
Speciﬁcation. SESAR Joint Undertaking, Aug2011.
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[4] ๺ં५, ॅ୩ହਓ, ੴग़໌. ରۭσʔλϦϯΫLDACS ෺ཧ૚ͷ࣮૷. ୈ 11 ճಠཱߦ੓๏ਓిࢠߤ๏‫ൃॴڀݚ‬දձߨԋ֓ཁ, pp. 25–28,June 2011.
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