ㄗࡾゞṇ➢ྕ໬ MC-CDMA ࡟࠾ࡅࡿ

Joint Multiuser Detection and Decoding in Coded MC-CDMA System 㸫

㸫 A Study on Quasi-Maximum-Likelihood Decoding using Ordered Statistics Algorithm 㸫

Naoya SHIBATA^*, Takayuki SHIMIZU ^*, Hisato IWAI^* and Hideichi SASAOKA^*

(Received January 20, 2011)

In multi-carrier code division multiple access (MC-CDMA) systems, delay waves cause inter-code interference and degrade bit error rate (BER) performance as the number of multiplexing users increases. In this paper, we propose a new quasi-maximum likelihood detection which jointly performs multiuser detection and error correction decoding for coded MC-CDMA systems to mitigate the inter-code interference. The proposed method uses codewords generated by the ordered statistics decoding for the quasi-maximum likelihood detection. In the proposed method, we only consider the codewords which have relatively high reliability values, where the reliability values are calculated from received signals, so that we can significantly decrease the number of codewords considered in the quasi-maximum likelihood detection. As the result of numerical simulations, we show that the proposed method exhibits better BER performance than a conventional method.

.H\ZRUGV : MC-CDMA, multiuser detection, inter-code interference, quasi-maximum likelihood decoding, ordered statistics decoding

࣮࣮࢟࣡ࢻ MC-CDMA

㸪࣐ࣝࢳ࣮ࣘࢨ᳨ฟ㸪ࢥ࣮ࢻ㛫ᖸ΅㸪‽᭱ᑬ᚟ྕ㸪㡰ᗎ⤫ィ㔞᚟ྕ

ㄗࡾゞṇ➢ྕ໬ MC-CDMA ࡟࠾ࡅࡿ

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮᪉ᘧ

㸫㡰ᗎ⤫ィ㔞࢔ࣝࢦࣜࢬ࣒ࢆ⏝࠸ࡓ‽᭱ᑬ᚟ྕἲࡢ᳨ウ㸫

Ⱚ⏣ ┤ஓ㸪ΎỈ ᓫஅ㸪ᒾ஭ ㄔே㸪➲ᒸ ⚽୍

ࡲ࠼ࡀࡁ

⛣ື㏻ಙ࡟࠾ࡅࡿ㸪㧗㏿࣭኱ᐜ㔞↓⥺࢔ࢡࢭࢫᢏ

⾡࡜ࡋ࡚㸪MC-CDMA㸦Multi-Carrier Code Division

Multiple Access㸧᪉ᘧࡀ࠶ࡿ㸬ࡇࡢ᪉ᘧࡣ OFDM

㸦Orthogonal Frequency Division Multiplexing㸧᪉ᘧ

࡜CDMA㸦Code Division Multiple Access㸧᪉ᘧࡢ฼

Ⅼࢆά࠿ࡋࡓከ㔜࢔ࢡࢭࢫᢏ⾡࡛࠶ࡿ^1-2)㸬

MC-CDMA ᪉ᘧ࡟࠾࠸࡚ࡣ࿘Ἴᩘ㡿ᇦ࡛ࡢᣑᩓ

➢ྕ࡟Walsh➢ྕࡀ୍⯡ⓗ࡟⏝࠸ࡽࢀ࡚࠸ࡿ㸬ࡑࡢ

㝿㸪㐜ᘏἼࡢᙳ㡪࡟ࡼࡾ㸪࣮ࣘࢨ㛫ࡢ┤஺ᛶࡀᔂࢀ㸪 ࢥ࣮ࢻ㛫ᖸ΅࡟ࡼࡾBER㸦Bit Error Rate㸧≉ᛶࡀຎ

໬ࡍࡿၥ㢟ࡀ࠶ࡿ㸬ࡇࡢᑐ⟇࡜ࡋ࡚㸪᚟ㄪ᫬࡟㔜ࡳ

ಀ ᩘ ࢆ ⏝ ࠸ ࡚ ྜ ᡂ ࡍ ࡿ 㸪 ┤ ஺ ໬ ྜ ᡂ(ORC:

Orthogonality Restoring Combining)ࡸ᭱ᑠᖹᆒ஧஌

ㄗ ᕪ ྜ ᡂ(MMSEC: Minimum Mean Square Error Combining)ࡀ࠶ࡿ㸬ࡇࢀࡽࡢ᪉ᘧ࡟ࡼࡾ㸪ከ㔜ᩘࡀ

* Department of Electronics, Doshisha University, Kyotanabe, Kyoto, 610-0321, Japan Telephone: +81-774-65-6355, Fax: +81-774-65-6801, E-mail: [email protected]

㸫 㸫

.H\ZRUGV

࣮࣮࢟࣡ࢻ

ㄗࡾゞṇ➢ྕ໬ ࡟࠾ࡅࡿ

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮᪉ᘧ

㸫㡰ᗎ⤫ィ㔞࢔ࣝࢦࣜࢬ࣒ࢆ⏝࠸ࡓ‽᭱ᑬ᚟ྕἲࡢ᳨ウ㸫

ࡲ࠼ࡀࡁ

ᑡ࡞࠸ሙྜ࡟ࡣࢥ࣮ࢻ㛫ᖸ΅ࢆᢚ࠼ࡿࡇ࡜ࡀ࡛ࡁ

ࡿࡀ㸪ከ㔜ᩘࡀቑຍࡍࡿ࡜ᣑᩓ➢ྕ㛫ࡢ┤஺ᛶࢆಖ ࡘࡇ࡜ࡣ࡛ࡁࡎ㸪ࢥ࣮ࢻ㛫ᖸ΅࡟ࡼࡾ BER≉ᛶࡣ

୍⯡࡟ຎ໬ࡍࡿ^3-4)㸬

ࢥ࣮ࢻ㛫ᖸ΅ࢆపῶࡍࡿᢏ⾡ࡢ୍ࡘ࡜ࡋ࡚࣐ࣝ

ࢳ࣮ࣘࢨ᳨ฟἲࡀ࠶ࡾ㸪BER ≉ᛶࡢ᭱ࡶඃࢀࡓᡭ ἲ࡜ࡋ࡚᭱ᑬ᳨ฟࡀᣲࡆࡽࢀࡿ㸬᭱ᑬ᳨ฟࡣ㸪௚ࡢ ᪉ᘧ࡟ẚ࡭࡚ㄗࡾ⋡ࢆ᭱ࡶᑠࡉࡃࡍࡿࡇ࡜ࡀ࡛ࡁ

ࡿࡀ㸪⥲ᙜࡓࡾࡢ᭱ᑬ᳨ฟ࡛ࡣ M ್ࡢኚㄪ᪉ᘧ㸪 ከ㔜ᩘ x ࡢሙྜ࡛ࡣܯ^௫㏻ࡾࡢ⣔ิ࠿ࡽ᭱ᑬࡢ⣔ิ

ࢆ㑅ᢥࡍࡿᚲせࡀ࠶ࡿ㸬ࡇࡢࡓࡵከ㔜ᩘxࡢቑຍ࡟

క࠸ィ⟬㔞ࡀᣦᩘⓗ࡟ቑຍࡍࡿ࡜࠸࠺ၥ㢟ࡀ࠶ࡿ㸬

⥲ᙜࡓࡾ࡟᳨ฟࢆ⾜࠺ࡢ࡛ࡣ࡞ࡃ,ೃ⿵ᩘࢆᢚ࠼ࡿ

᪉ἲ࡜ࡋ࡚௬ุᐃࢹ࣮ࢱࡢ㏆ഐ᥈⣴ࢆ⾜࠺ࡇ࡜࡛

㏦ಙࢹ࣮ࢱೃ⿵ࢆ⏕ᡂࡋ㸪ẚ㍑ィ⟬ࡍࡿೃ⿵ᩘࢆᢚ

࠼ࡓ‽᭱ᑬ᳨ฟ᪉ᘧࡀ࠶ࡿ²⁾㸬‽᭱ᑬ᳨ฟ᪉ᘧ࡛ຠ

⋡ࡼࡃ BER≉ᛶࢆᨵၿࡍࡿࡓࡵ࡟ࡣຠᯝⓗ࡟㏆ഐ ᥈⣴ࢆ⾜࠺ᚲせࡀ࠶ࡿ㸬ࡑࡇ࡛➢ྕ໬ MC-CDMA ࢩࢫࢸ࣒࡟㐺⏝ࡍࡿ‽᭱ᑬ᳨ฟ᪉ᘧࡢᡭἲ࡜ࡋ࡚

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࢆ୍య໬ࡋ࡚ฎ

⌮ࢆ⾜࠺᪉ᘧࡀ࠶ࡿ⁵⁾㸬ࡇࡢ᪉ἲ࡛ࡣ㸪ೃ⿵ࡣ➢ྕ

ㄒࡢࡳ࡟㝈ᐃࡉࢀ௬ุᐃࢹ࣮ࢱࡢ㏆ഐ᥈⣴ࡢ⡆␎

໬ࡀྍ⬟࡜࡞ࡗ࡚࠸ࡿ㸬ᩥ⊩5)ࡢ୍య໬ฎ⌮᪉ᘧ࡛

ࡣ㸪㏦ಙㄒೃ⿵⏕ᡂ࡟ࢸ࣮ࣈࣝཧ↷᚟ྕἲ⁶⁾ࢆ⏝࠸

ࡿࡇ࡜࡟ࡼࡾ㸪ຠ⋡ⓗ࡟‽᭱ᑬ᳨ฟࢆ⾜ࡗ࡚࠸ࡿ㸬 ࢸ࣮ࣈࣝཧ↷᚟ྕἲ࡛ࡣ᚟ྕࢆ⾜࠺ࡓࡵ࡟ྛࢩࣥ

ࢻ࣮࣒ࣟ࡟ᑐᛂࡋࡓㄗࡾ⣔ิࡢࣜࢫࢺ(ࢸ࣮ࣈࣝ)ࢆ

࠶ࡽ࠿ࡌࡵ࣓ࣔࣜ࡟ಖᏑࡋ࡚࠾ࡁ㸪ࡑࢀ࡜ཷಙ⣔ิ

ࢆẚ㍑ࡍࡿࡇ࡜࡛ຠ⋡໬ࢆᅗࡗ࡚࠸ࡿ㸬ࡋ࠿ࡋ㸪➢

ྕ㛗ࡀቑຍࡍࡿ࡜ㄗࡾ⣔ิࡢಶᩘࡀቑຍࡋ㸪౑⏝ࡍ

ࡿ࣓ࣔࣜ㔞ࡀ⭾኱࡜࡞ࡿၥ㢟ࡀ࠶ࡿ㸬ࡑࡇ࡛ᮏ◊✲

࡛ࡣ㸪‽᭱ᑬ᳨ฟࢆ⾜࠺㏦ಙㄒೃ⿵⏕ᡂ࡟㸪㡰ᗎ⤫

ィ㔞᚟ྕ⁷⁾ࡢᡭἲࢆ⏝࠸ࡿ᪉ᘧࢆᥦ᱌ࡍࡿ㸬ᥦ᱌᪉ ᘧ࡛ࡣࢸ࣮ࣈࣝཧ↷᚟ྕἲࡢࡼ࠺࡟஦๓࡟࣓ࣔࣜ

࡟ㄗࡾ⣔ิࢆグ㘓ࡋ࡚࠾ࡃᚲせࡀ࡞࠸ࡓࡵ㸪ᚲせ࡞

࣓ࣔࣜࡀᑡ࡞ࡃ࡚ࡍࡴ㸬ࡲࡓ㸪ཷಙಙྕ࠿ࡽồࡵࡓ ಙ㢗ᗘࢆ⏝࠸࡚ೃ⿵ࢆ⏕ᡂࡍࡿࡇ࡜࡛ㄗࡾ⋡≉ᛶ ࡢᨵၿࡀᮇᚅ࡛ࡁࡿ㸬ᮏ◊✲࡛ࡣ㸪ࡇࡢᥦ᱌᪉ᘧࡢ

᭷ຠᛶࢆィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ࡟ࡼࡾホ౯ࡍࡿ㸬

‽᭱ᑬ᳨ฟ

‽᭱ᑬ᳨ฟࡢ᭷ຊ࡞ࡶࡢࡣ௬ุᐃࢹ࣮ࢱ࠿ࡽࡢ

㏆ഐ᥈⣴࡛࠶ࡿ㸬ࡑࡢ୍౛࡜ࡋ࡚௬ุᐃࢹ࣮ࢱ࠿ࡽ

1ࣅࢵࢺ㏆ഐࡢ඲᥈⣴㸦1ࣅࢵࢺኚ᥮㸧ࡀ࠶ࡿ⁵⁾㸬

Fig. 1࡟1ࣅࢵࢺኚ᥮࡟ࡼࡿ‽᭱ᑬ᳨ฟἲࡢὶࢀ

ࢆ♧ࡍ㸬ࡲࡓ㸪ᮏ◊✲࡛ࡣ࿘Ἴᩘ㍈᪉ྥ࡟ࢹ࣮ࢱࢆ

ᣑᩓࡋ㸪ከ㔜໬ᚋS/Pኚ᥮ࢆ⾜࠸IFFTࡍࡿฎ⌮ࢆ

MC-CDMAኚㄪ࡜࿧ࡧ㸪ཷಙಙྕ࡟ FFT ࢆ⾜࠸㏫

ᣑᩓࡍࡿฎ⌮ࢆMC-CDMA᚟ㄪ࡜࿧ࡪࡇ࡜࡟ࡍࡿ㸬

Fig. 2࡟ᮏ◊✲࡛ᑐ㇟࡜ࡍࡿࢩࢫࢸ࣒࡟࠾ࡅࡿከ㔜

ᩘn(n<L)࡜࡞ࡿMC-CDMAኚㄪࢆ♧ࡋ㸪Fig. 3࡟ MC-CDMA᚟ㄪࢆ♧ࡍ㸬Fig. 2, Fig. 3࡛♧ࡍc_i=(c_i,1,

͐, c_i,L)ࡣ࿘Ἴᩘ㡿ᇦ࡟ࢹ࣮ࢱࢆᣑᩓࡍࡿ L™L ࡢ Walsh➢ྕC_w=(c₁,͐, c_L)ࡢ⣔ิ࡛࠶ࡾ(L:ᣑᩓ⋡)㸪

Fig. 3࡛♧ࡍE_Lࡣᣑᩓ᚟ㄪ࡟⏝࠸ࡿ㔜ࡳಀᩘ࡛࠶ࡿ㸬

1ࣅࢵࢺኚ᥮࡟ࡼࡿ‽᭱ᑬ᳨ฟ࡛ࡣ㸪MMSEC࡟

ࡼࡿ㔜ࡳ࡙ࡅ࡛᚟ㄪࡋࡓࢹ࣮ࢱࢆ௬ุᐃࢹ࣮ࢱ࡜

ࡋ㸪௬ุᐃࢹ࣮ࢱࡢ1ࣅࢵࢺࢆ㡰ḟኚ໬ࡉࡏࡓࡶࡢ ࡢࡳࢆ㏦ಙࢹ࣮ࢱೃ⿵࡜ࡍࡿ㸬2್ኚㄪ࡛ከ㔜ᩘࡀ xࡢሙྜ㸪᭱ᑬ᥎ᐃ࡛ࡣ2^x㏻ࡾࡢ㏦ಙࢹ࣮ࢱೃ⿵ࢆ

⏕ᡂࡍࡿࡀ㸪ࡇࡢࡼ࠺࡞‽᭱ᑬ᳨ฟ࡛ࡣೃ⿵ᩘࡣ ݔ ൅ ͳಶ࡜࡞ࡾ㸪₇⟬㔞ࡢቑຍࢆᣦᩘⓗ࡞ࡶࡢ࠿ࡽ

ከ㔜ᩘxࡢ1஌ࡢ࣮࢜ࢲ࣮࡟ᢚ࠼ࡿࡇ࡜ࡀ࡛ࡁࡿ㸬 ࡋ࠿ࡋ㸪ከ㔜ᩘࡀቑຍࡋᖸ΅ࡢᙳ㡪ࡀ኱ࡁ࠸࡜ㄗࡾ

ಶᩘࡶቑ࠼㸪༢⣧࡟௬ุᐃ࠿ࡽ1ࣅࢵࢺ㏆ഐࡢೃ⿵

ࢆ㑅ࡪࡔࡅ࡛ࡣBER ≉ᛶࡣ࠶ࡲࡾᨵၿࡉࢀ࡞࠸㸬

ࡼࡗ࡚㸪ከ㔜ᩘࡢከ࠸ࢥ࣮ࢻ㛫ᖸ΅ࡢᙳ㡪ࢆᨵၿࡍ

ࡿࡓࡵ࡟ࡣ㸪ຠᯝⓗ࡞㏆ഐ᥈⣴ࡢ᪉ἲࡀồࡵࡽࢀࡿ㸬

࡞࠾㸪ᮏ◊✲࡛㐺⏝ࡍࡿ࣐ࣝࢳ࣮ࣘࢨ᳨ฟࡣ㸪⏕

ᡂࡋࡓೃ⿵࠿ࡽ㏦ಙಙྕࣞࣉࣜ࢝ࢆసࡾ㸪ཷಙಙྕ

࡜ࡢ࣮ࣘࢡࣜࢵࢻ㊥㞳ẚ㍑࡟ࡼࡾ⾜࠺㸬࣮ࣘࢡࣜࢵ

ࢻ㊥㞳ࡀ᭱ᑠ࡜࡞ࡿೃ⿵ࢆ᭱ᑬ࡞ೃ⿵࡜᥎ᐃࡍࡿ

ࡇ࡜࡛ཷಙᛶ⬟ࢆྥୖࡉࡏࡿࡇ࡜ࡀ࡛ࡁࡿ㸬ࡲࡓ㸪 ᑐ㇟࡜ࡍࡿ MC-CDMA ࢩࢫࢸ࣒ࡣ㸪ᣑᩓ➢ྕࡢ┤

஺໬ࡉࢀࡓ」ᩘࡢ⣔ิࢆ 1 ࣮ࣘࢨࡢࡳࡀ⏝࠸࡚ከ 㔜ఏ㏦ࢆ⾜࠺ࡶࡢ࡛࠶ࡾ㸪ཝᐦ࡞ព࿡࡛ࡢ࣐ࣝࢳࣘ

࣮ࢨఏ㏦࡛ࡣ࡞࠸㸬ࡋ࠿ࡋ㸪ࡇࡢᡭἲࡣ୍⯡ⓗ࡞࣐

ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ྠᵝࡢฎ⌮ࢆ⾜࠺ࡓࡵ㸪ᮏ◊✲࡛

ࡣከ㔜ࢹ࣮ࢱ࡟ᑐࡋ࡚⾜࠺᳨ฟࢆ࣐ࣝࢳ࣮ࣘࢨ᳨

ฟ࡜࿧ࡪࡇ࡜࡟ࡍࡿ㸬

Fig. 1. Quasi-Maximum-Likelihood-Detection using 1-bit conversion method

Fig. 2. MC-CDMA modulation

Fig. 3. MC-CDMA demodulation

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮

‽᭱ᑬ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡣ஫࠸࡟⊂❧࡟ฎ⌮

ࡋ࡚ࡶⰋ࠸ࡀ㸪ࡇࢀࡽࡢฎ⌮ࢆ୍య໬ࡋ࡚ฎ⌮ࡍࡿ

ࡇ࡜࡛㸪ࡼࡾ BER≉ᛶࢆᨵၿࡍࡿࡇ࡜ࡀ࡛ࡁࡿ㸬 ࡇࡢ᪉ἲ࡛ࡣ‽᭱ᑬ᳨ฟ࡟⏝࠸ࡿೃ⿵ࡣ➢ྕㄒࡢ

ࡳ࡟㝈ᐃࡉࢀ௬ุᐃࢹ࣮ࢱࡢ㏆ഐ᥈⣴ࡢ⡆␎໬ࡀ

ྍ⬟࡜࡞ࡗ࡚࠸ࡿ㸬ࡑࡇ࡛㸪ࡇࡇ࡛ࡣ࣐ࣝࢳ࣮ࣘࢨ

᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮ࢆᑐ㇟࡜ࡍࡿ㸬 Fig. 4࡟➢ྕ໬MC-CDMAࡢ㏦ಙᶵᵓᡂࢆ♧ࡍ㸬Fig.

5࡟ࡣㄗࡾゞṇ᚟ྕࢆಶู࡟⾜࠺୍⯡ⓗ࡞ሙྜࢆ♧

ࡋ㸪Fig. 6࡟ࡣ࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜୍య໬ࡋ࡚⾜࠺

ሙ ྜ ࡢ ཷ ಙ ᶵ ᵓ ᡂ ࢆ ࡑ ࢀ ࡒ ࢀ ♧ ࡍ 㸬 ➢ ྕ ໬

MC-CDMAࡢࢹ࣮ࢱ㏦ಙ࡛ࡣ㸪Fig. 4࡟♧ࡍ㏦ಙᶵ

࡟࠾࠸࡚kࣅࢵࢺࡢ㏦ಙࢹ࣮ࢱd=(d₁,͐, d_k)ࡣㄗࡾ

ゞṇ➢ྕ໬ࡉࢀnࣅࢵࢺ(n>k)ࡢt㔜ㄗࡾゞṇ➢ྕㄒ d_c=(d_c1,͐, d_cn)࡜࡞ࡿ㸬➢ྕ໬ᚋ㸪୍ḟኚㄪࡉࢀࡓࢹ

࣮ࢱࢩࣥ࣎ࣝࡣL™LࡢWalsh➢ྕ⾜ิC_wࡢ࠺ࡕL

™nࡢ⾜ิC࡟ࡼࡾᣑᩓࡉࢀከ㔜໬ࡉࢀࡿ㸬ࡑࡋ࡚

IFFTᚋP/Sኚ᥮ࡉࢀ➢ྕ໬MC-CDMAࢩࣥ࣎ࣝ࡜

࡞ࡿ㸬

Fig. 6࡟♧ࡍ࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ

୍య໬ฎ⌮࡛ࡣ㸪ཷಙᶵ࡟࠾࠸࡚࣐ࣝࢳ࣮ࣘࢨ᳨ฟ

ࢆ ⾜ ࠺ ࣞ ࣉ ࣜ ࢝ ࢩ ࣥ ࣎ ࣝ ࢆ స ࡿ 㸬 ཷ ಙ ᶵ ࡛

MC-CDMA᚟ㄪ࡟࠾ࡅࡿFFTฎ⌮ࡢᚋ㸪S/Pኚ᥮ࡋ

ࡓཷಙಙྕ࣋ࢡࢺࣝࢆy=[y₁,͐,y_L]^T࡜ࡍࡿ࡜௨ୗࡢ

ࡼ࠺࡟⾲ࢃࡏࡿ㸬

n Cd H

y _{ch c}^T (1)

ࡇࡇ࡛㸪H_ch㸻diag[h_ch1,͐,h_chL]ࡣL™Lࡢఏ㏦㊰ࡢ

࿘Ἴᩘᛂ⟅ࢆᑐゅᡂศ࡟ᣢࡘᑐゅ⾜ิ࡛࠶ࡿ㸬nࡣ ຍἲᛶⓑⰍ࢞࢘ࢫ㞧㡢࣋ࢡࢺ࡛ࣝ࠶ࡿ㸬ࣞࣉࣜ࢝ࢆ

⏕ᡂࡍࡿࡓࡵ࡟㸪ࡲࡎཷಙಙྕyࢆ᚟ㄪࡍࡿ㸬ࡇࢀ

ࢆᇶ࡟㏦ಙࡉࢀࡓ࡜⪃࠼ࡽࢀࡿ➢ྕㄒࡢೃ⿵ d_cԢࢆ

⏕ᡂࡍࡿ㸬⏕ᡂࡋࡓ」ᩘࡢࣞࣉࣜ࢝ࡢ࠺ࡕཷಙಙྕ

࡜ࡢ஧஌࣮ࣘࢡࣜࢵࢻ㊥㞳||y㸫H_ch C d_cԢ^T||²ࢆ᭱ᑡ࡜

ࡍࡿೃ⿵ d_cԢࡀ㏦ಙࡉࢀࡓ➢ྕㄒࡔ࡜᥎ᐃࡍࡿ㸬௨

ୖࡢฎ⌮ࡼࡾ㸪࣮ࣘࢡࣜࢵࢻ㊥㞳ẚ㍑ࢆ⾜࠺࣐ࣝࢳ

࣮ࣘࢨ᳨ฟ࡟ࡼࡗ࡚㸪ㄗࡾゞṇࡉࢀࡓ➢ྕㄒࡀ᥎ᐃ ࡉࢀࡿࡢ࡛㸪࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡀ୍

య໬ࡋ࡚ฎ⌮ࡉࢀࡓࡇ࡜࡟࡞ࡿ㸬ࡇࡢࡼ࠺࡞୍య໬

ฎ⌮ࢆ⾜࠺ࡇ࡜࡛㸪㏦ಙࢹ࣮ࢱࡢೃ⿵ࡀ➢ྕㄒࡔࡅ

࡟㝈ᐃࡉࢀࡿ㸬ࡲࡓ㸪࣮ࣘࢡࣜࢵࢻ㊥㞳ẚ㍑࡟ࡼࡾ

᚟ྕㄒࢆ᥎ᐃࡍࡿࡢ࡛㸪◳ุᐃ᚟ྕ࡛t㔜ㄗࡾゞṇ ࡀྍ⬟࡞➢ྕ࡟㐺⏝ࡋࡓሙྜ࡛ࡶ㸪t+1௨ୖࡢㄗࡾ

ゞṇࡀྍ⬟࡜࡞ࡿ㸬

Fig. 4. Coded MC-CDMA transmitter

Fig. 5. Coded MC-CDMA receiver (Serial decoding process㸧

Fig. 6. Coded MC-CDMA receiver (Joint multiuser detection and decoding)

MC-CDMA demodulation

Generation of candidates for transmitted data by one-bit conversion method

MC-CDMA modulation

Multiuser Detection Received signal

( Multiplexing x)

x+1 number of candidate

Estimated Data

IFFT P/S

S/P c₁

c_n c₂

S/P ¦

n 1 Data symbols

d=(d₁,…,d_n) ^MC-CDMA symbol

FFT E1c1,1

E_Lc_{1, L} E2c1,2

n¦ 1

S/P P/S

cn,1~Lsequence c2,1~Lsequence

Received

signal MC-CDMA

demod data

Error correction

coding Modulation MC-CDMA

Modulation Transmit data

d=(d₁,…,d_k)

Transmit signal Cordword

d_c=(d_c1,…,d_cn)

Received signal MC-CDMA demodulation

Error correction decoding

Decoded data

MC-CDMA demodulation

Generation of candidates for transmitted code

MC-CDMA modilation

Comparison of Euclidean distance

Replica symbols

Decoded Received symbol data

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮

ࢸ࣮ࣈࣝཧ↷࡟ࡼࡿ㏦ಙ➢ྕㄒೃ⿵ࡢ⏕ᡂἲ

࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮

࡟࠾࠸࡚㸪ࢸ࣮ࣈࣝཧ↷᚟ྕ⁶⁾ࡢᡭἲࢆ⏝࠸ࡓ㏦ಙ

➢ྕㄒೃ⿵ࡢ⏕ᡂἲࢆ♧ࡍ㸬Fig. 7࡟ࢸ࣮ࣈࣝཧ↷

᚟ྕἲࢆ⏝࠸ࡓ㏦ಙ➢ྕㄒೃ⿵⏕ᡂࡢὶࢀࢆ♧ࡍ㸬 ࢸ࣮ࣈࣝཧ↷᚟ྕἲ࡛ࡣཷಙᶵ࡛ MC㸫CDMA ᚟ ㄪࡋࡓ௬ุᐃࢹ࣮ࢱࡢ㏆ഐࡢ㸦ࣁ࣑ࣥࢢ㊥㞳ࡢ㏆࠸㸧

➢ྕㄒࢆ㏦ಙㄒೃ⿵࡜ࡋ࡚⏕ᡂࡍࡿ㸬௬ุᐃࢹ࣮ࢱ

࠿ࡽࢩࣥࢻ࣮࣒ࣟࢆồࡵ㸪ࢩࣥࢻ࣮࣒ࣟࢆ⏝࠸࡚ࢸ

࣮ࣈࣝࢆཧ↷ࡍࡿࡇ࡜࡛㸪ྠࡌࢩࣥࢻ࣮࣒ࣟࡀ⏕ࡌ

ࡿ」ᩘࡢㄗࡾࣃࢱ࣮ࣥࢆᚓࡿࡇ࡜ࡀ࡛ࡁࡿ㸬ཧ↷ࡋ ࡓㄗࡾࣃࢱ࣮ࣥࢆ◳ุᐃࢹ࣮ࢱ࡟௜ຍࡍࡿࡇ࡜࡛

㏦ಙ➢ྕㄒೃ⿵⩌ࡀ⏕ᡂࡉࢀࡿ㸬

ࡇࡢ᪉ᘧ࡛⏝࠸ࡿࢸ࣮ࣈࣝࡣ㸪ࢩࣥࢻ࣮࣒ࣟ㛗m

࡟ᑐࡋ࡚ 2^m✀㢮ࡢࢩࣥࢻ࣮࣒ࣟ࡜ࡑࡢࢩࣥࢻ࣮ࣟ

࣒࡟ᑐᛂࡍࡿⓎ⏕☜⋡ࡢ㧗࠸ㄗࡾࣃࢱ࣮ࣥ࡜ࡢᑐ ᛂ⾲࡛࠶ࡿ㸬ࡇࡇ࡛ㄗࡾࣃࢱ࣮ࣥ࡜ࡣ㸪ཷಙಙྕࢆ

MC-CDMA᚟ㄪᚋࡢ◳ุᐃ⣔ิ࡟ᑐࡋ㸪ㄗࡾࣅࢵࢺ

఩⨨ࡀ1㸪ࡑࢀ௨እࡢࣅࢵࢺ఩⨨ࡀ0࡛⾲ࢃࡉࢀ࡚

࠸ࡿ2್⣔ิࡢࡇ࡜࡛࠶ࡿ㸬ࢸ࣮ࣈࣝసᡂ࡟࠶ࡓࡾ㸪 ࢩࣥࢻ࣮࣒ࣟࢆ⏕ᡂࡍࡿㄗࡾ⣔ิ e₀=(e₀₁,e₀₂,͐e_0n) ࡢ᭱኱ࣁ࣑ࣥࢢ㔜ࡳࢆ᚟ྕ༙ᚄ d_D࡜ࡍࡿ㸬ࢸ࣮ࣈ

ࣝసᡂࡣ஦๓࡟タᐃࡋࡓࣁ࣑ࣥࢢ㔜ࡳ d_D௨ୗࡢㄗ

ࡾ⣔ิࡢࢩࣥࢻ࣮࣒ࣟィ⟬ࢆࡋ࡚࠾ࡁ㸪ྛࢩࣥࢻࣟ

࣮࣒࡟ᑐᛂࡉࡏ࡚࣓ࣔࣜ࡟ಖᏑࡋ࡚࠾ࡃ㸬࡞࠾㸪d_D ࡢ኱ࡁࡉ࡟ᑐᛂࡋ࡚㸪ㄗࡾࣃࢱ࣮ࣥࡢಶᩘࡀቑ࠼㸪

㏦ಙ➢ྕㄒೃ⿵ࡀቑຍࡍࡿ㸬

Fig. 7. Generation of candidates by table-aided decoding for the quasi-maximum likelihood detection

㡰ᗎ⤫ィ㔞࡟ࡼࡿ㏦ಙ➢ྕㄒೃ⿵ࡢ⏕ᡂἲ ๓㏙ࡋࡓࢸ࣮ࣈࣝཧ↷᚟ྕࡢᡭἲࢆ⏝࠸ࡓ㏦ಙ

➢ྕㄒೃ⿵ࡢ⏕ᡂ࡛ࡣཷಙᶵ࡛ㄗࡾࣃࢱ࣮ࣥࡢࢸ

࣮ࣈࣝࢆಖᣢࡋ࡚࠾ࡃᚲせࡀ࠶ࡿ㸬ࡋ࠿ࡋ㸪➢ྕ㛗 ࡀቑຍࡍࡿ࡜ㄗࡾ⣔ิࡢಶᩘࡀቑຍࡋ㸪౑⏝ࡍࡿ࣓

ࣔࣜ㔞ࡀ⭾኱࡜࡞ࡿၥ㢟ࡀ࠶ࡿ㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣ㸪 ࢸ࣮ࣈࣝࡢಖᏑࢆᚲせ࡜ࡏࡎຠᯝⓗ࡟ೃ⿵ࢆ⏕ᡂ ࡍࡿᡭἲࢆᥦ᱌ࡍࡿ㸬ᥦ᱌᪉ᘧ࡛ࡣ㸪㡰ᗎ⤫ィ㔞᚟

ྕࡢᡭἲࢆ⏝࠸࡚㏦ಙ➢ྕㄒೃ⿵ࢆ⏕ᡂࡋ୍య໬

ฎ⌮ࢆ⾜࠺㸬㡰ᗎ⤫ィ㔞᚟ྕ࡛ࡣ㸪ࢹ࣮ࢱࡢಙ㢗ᗘ

ࢆ⪃៖ࡋಙ㢗ᗘࡢప࠸ࣅࢵࢺ࡟ᑐࡋ࡚ㄗࡾゞṇࢆ

⾜࠺㸬ࡼࡗ࡚㸪࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡟౑⏝ࡍࡿ➢ྕㄒ ࡣ᥎ᐃ⢭ᗘࡢ㧗࠸㏦ಙㄒೃ⿵࡜࡞ࡿ㸬ࡲࡓ㸪ࢹ࣮ࢱ ࡢಙ㢗ᗘ࡟ࡣ㏫ᣑᩓ᚟ㄪᚋࡢ㌾ุᐃࢹ࣮ࢱ࠿ࡽྛ

ࣅࢵࢺࡢLLR(Log Likelihood Ratio)ࢆồࡵ㸪LLRࡢ

⤯ᑐ್ࢆྛࣅࢵࢺࡢಙ㢗ᗘ࡜ࡋ࡚⏝࠸ࡿ㸬ࡑࡇ࡛㸪

ࡲࡎ㸪LLR࡟ࡘ࠸࡚㏙࡭ࡿ㸬

ಙ㢗ᗘ࡜ࡋ࡚⏝࠸ࡿLLR

ཷಙᶵ࡟࠾࠸࡚ MC-CDMAࡢ1 ࢩࣥ࣎ࣝࢆ᚟ㄪ ࡋࡓi␒┠ࡢ᚟ㄪࢹ࣮ࢱr_iࡣ

i dii

gii

ri H_iW

¦

z 1 K

i l

i di

gil H

(2)

࡜⾲ࡉࢀࡿ㸬ࡓࡔࡋ㸪g_iid_iࡣᕼᮃಙྕᡂศ㸪H_iࡣࢥ

࣮ࢻ㛫ᖸ΅ᡂศ㸪W_iࡣ࢞࢘ࢫ㞧㡢ᡂศ࡛࠶ࡾ㸪ᖹᆒ 0 ࡛ศᩓࡀV_Wࡢ࢞࢘ࢫ☜⋡ኚᩘ࡜ࡍࡿ㸬ࡇࡇ࡛ g_il ࡣḟᘧ࡟♧ࡍ⾜ิGࡢ(i,l)せ⣲࡛࠶ࡿ㸬

G㸻C^HW H_ch C (3) ࡇࡇ࡛㸪Hࡣ࢚࣑࣮ࣝࢺ㌿⨨ࢆ⾲ࡋ㸪Wࡣᣑᩓ᚟ㄪ

࡟⏝࠸ࡿ㔜ࡳ௜ࡅ࡛࠶ࡿ㸬ࡲࡓ㸪ࢥ࣮ࢻ㛫ᖸ΅ᡂศ H_iࡣ୰ᚰᴟ㝈ᐃ⌮ࡼࡾ㸪㏆ఝⓗ࡟ᖹᆒ0࡛ศᩓࡀV_H ࡢ࢞࢘ࢫ☜⋡ኚᩘ࡛࠶ࡿ࡜ࡍࡿ㸬ᮏ◊✲࡛᝿ᐃࡍࡿ

ࢩࢫࢸ࣒࡛ࡣV_H࡜V_Wࡣ࢖ࣥࢹࢵࢡࢫi࡟ࡼࡽࡎ㸪H_i

࡜W_iࡣ⤫ィⓗ࡟⊂❧࡛࠶ࡿ࡜ࡍࡿࡢ࡛㸪d_iࡢ᮲௳௜

ࡁ࡛ࡢ r_iࡢ☜⋡ᐦᗘ㛵ᩘࡣ௨ୗࡢࡼ࠺࡟⾲ࡍࡇ࡜

ࡀ࡛ࡁࡿ㸬

¸¸

¸

¹

·

¨¨

¨

©

§

2

2 2 2

2 exp

) (

) 1 (

W H W

H V V V

V

S ⁱ

iid g r d

r

p _{i i} ^{i (4)}

ࡇ ࡇ ࡛ 㸪ML つ ⠊ ࡟ ᇶ ࡙ ࡃ ◳ ุ ᐃ ࢹ ࣮ ࢱ݀መ௜ࡣ

݀መ_௜ൌ ƒ”‰ ‹_ୢ೔ȳሺ݀_௜ሻ࡛⾲ࡉࢀࡿ㸬ࡇࡢ࡜ࡁ:(d_i)ࡣ

ḟᘧ࡜ࡍࡿ㸬

) 2

(d_i r_igiidi

: (5)

࡞࠾㸪MMSEC ࡢ⥺ᙧࣇ࢕ࣝࢱࢆ㐺⏝ࡍࡿሙྜ g_ii ࡢ್ࡣࡍ࡭࡚➼ࡋࡃ࡞ࡿࡢ࡛㸪g࡜᭩ࡁ᥮࠼ࡿ㸬 ḟ࡟㸪2␒┠࡟:(d_i)ࢆᑠࡉࡃࡍࡿࢩࣥ࣎ࣝࢆ݀෩_ప࡜

⾲ࡋ㸪LLR(D_i࡜⾲グࡍࡿ)ࢆ௨ୗࡢࡼ࠺࡟ᐃ⩏ࡍࡿ㸬 ߙ_௜ൌ Ž‘‰^{୮൫௥೔หௗ೔ୀௗ෠೔൯}

୮൫௥_೔หௗ_೔ୀௗ෨_೔൯

(6)

ࡲࡓ㸪ከ್ኚㄪࡀBPSKࡢሙྜLLRࡣ㸪(4)ᘧ࠿ࡽ

ඹ㏻㡯࡜࡞ࡿศẕࢆ㝖ཤࡋࡓࡶࡢ࡜(5)ᘧࢆ⏝࠸࡚

ḟࡢࡼ࠺࡟⾲ࡍࡇ࡜ࡀ࡛ࡁࡿ㸬

ߙ௜ൌ _:(d^~_i):(d^ˆ_i) ൐ Ͳ (7) ࡇࡇ࡛Dࡣ◳ุᐃ݀መ௜ࡢಙ㢗ᗘࢆ♧ࡋ࡚࠾ࡾ㸪D_iࡀ኱

ࡁࡅࢀࡤ኱ࡁ࠸࡯࡝㸪ࢹ࣮ࢱࡢಙ㢗ᗘࡀ㧗࠸ࡇ࡜ࢆ

ព࿡ࡍࡿ⁸⁾㸬

ḟ࡟㸪QPSKࢆᑐ㇟࡜ࡍࡿ㸬QPSK࡟࠾ࡅࡿಙྕ

㓄⨨ࢆFig. 8࡟♧ࡍ㸬Fig. 8࡟♧ࡍࡼ࠺࡟㏫ᣑᩓ᚟

ㄪᚋࡢi␒┠ࡢQPSKཷಙࢹ࣮ࢱr_iࡢ1ࣅࢵࢺ┠ࢆ

r_{i ,1}㸪2ࣅࢵࢺ┠ࢆr_{i ,2}࡜ࡍࡿ㸬ࡲࡓQPSKಙྕ㓄⨨

࡟࠾ࡅࡿ1ࣅࢵࢺ┠ࢆb₁㸪2ࣅࢵࢺ┠ࢆb₂࡜ࡋ㸪㸦b_1㸪 b₂㸧ࡀ㸦0,0㸧ࢆS1㸪㸦0,1㸧ࢆS2㸪㸦1,1㸧ࢆS3㸪㸦1,0㸧

ࢆS₄⾲ࡋࡓሙྜ㸪Fig. 8࡟࠾ࡅࡿr_{i ,1}ࡢLLRࢆ⾲ࡍ α (r_{i ,1)}ࡣ

ߙ_{ሺ௥೔ǡଵሻ}ൌ Ž‘‰݌ሺݎ௜ȁܾ_ଵൌ Ͳሻ

݌ሺݎ_௜ȁܾ_ଵൌ ͳሻൌ Ž‘‰݌ሺݎ௜ȁܵ_ଵሻ ൅ ݌ሺݎ_௜ȁܵ_ସሻ

݌ሺݎ_௜ȁܵ_ଶሻ ൅ ݌ሺݎ_௜ȁܵ_ଷሻ

ൌ Ž‘‰

ୣ୶୮൬ି^{൫ೝ೔షౝ೔೔ೄభ൯}

഑ചమశ഑ഓమ ൰ାୣ୶୮൬ି^{൫ೝ೔షౝ೔೔ೄర൯}

഑ചమశ഑ഓమ ൰

ୣ୶୮൬ି^{൫ೝ೔షౝ೔೔ೄమ൯}

഑ചమశ഑ഓమ ൰ାୣ୶୮൬ି^{൫ೝ೔షౝ೔೔ೄయ൯}

഑ചమశ഑ഓమ ൰

(8)

࡜⾲ࡉࢀ㸪ศᩓࢆồࡵࡿᚲせࡀ࠶ࡿ㸬ࢥ࣮ࢻ㛫ᖸ΅

ᡂศࡢศᩓࡢ್ࡣᮍ▱࡛࠶ࡾ㸪ồࡵࡿࡇ࡜ࡀฟ᮶࡞

࠸ࡢ࡛㸪ศᩓࢆồࡵࡎ࡟ಙ㢗ᗘࢆ⏝࠸ࡿࡓࡵ࡟ᮏ◊

✲࡛ࡣୖᘧࢆ௨ୗࡢࡼ࠺࡟⡆␎໬ࡋ࡚ồࡵࡿࡇ࡜

࡟ࡍࡿ㸬

ߙ_ሺ௥೔ǡଵሻ؆ Ž‘‰^{୫ୟ୶ሺ௣ሺ௥೔ȁௌభሻǡ௣ሺ௥೔ȁௌరሻሻ}

୫ୟ୶ሺ௣ሺ௥_೔ȁௌ_మሻǡ௣ሺ௥_೔ȁௌ_యሻሻ (9)

ୖᘧ࡛ࡣ㸪ཷಙࢹ࣮ࢱ࡟࠾࠸࡚ᐇᩘ㒊㸪⹫ᩘ㒊࡟ᑐ ᛂࡍࡿྛࣅࢵࢺ࡟ᑐࡋ࡚㸪ᐇᩘ㒊ࡢࡳࡢ LLR ࡜⹫

ᩘ㒊ࡢࡳࡢLLRࢆồࡵࡿࡇ࡜ࡀ࡛ࡁࡿ㸬

Fig. 8. QPSK constellation diagram

㡰ᗎ⤫ィ㔞᚟ྕࡢᡭ㡰

ᑐ㇟࡜ࡍࡿ➢ྕ໬ MC-CDMA ࢩࢫࢸ࣒࡛ࡣ㸪➢

ྕ㛗n㸪᝟ሗ㛗k࡜ࡍࡿ2ඖ⥺ᙧࣈࣟࢵࢡ➢ྕࢆ⏝

࠸㸪᳨ᰝ⾜ิࢆH࡜ࡍࡿ㸬

Order-0ࡢ㡰ᗎ⤫ィ㔞᚟ྕ

ཷಙಙྕ࠿ࡽ MMSEC ࢆ⏝࠸ࡓ㔜ࡳ࡛㏫ᣑᩓ᚟

ㄪࡋࡓ⣔ิr = (r₁,r₂,͐,r_n)ࡢྛࣅࢵࢺr_i࠿ࡽಙ㢗ᗘ

࡜ࡋ࡚⏝࠸ࡿLLRࢆồࡵ㸪r_iࡢಙ㢗ᗘࢆD_ri࡜⾲ࡍ㸬 D_riࡢ್ࡀ㝆㡰࡜࡞ࡿࡼ࠺㸪rࢆ⨨᥮ࡍࡿ㸬ࡑࢀ࡟ࡼ

ࡗ࡚ᚓࡽࢀࡓ⣔ิࢆu = (u₁,u₂,͐u_n)࡜ࡍࡿ㸬ࡇࡢ࡜

ࡁ㸪uࡢྛࣅࢵࢺࡢಙ㢗ᗘD_ui࡟ᑐࡋ࡚ḟᘧࡀᡂࡾ❧

ࡘ㸬

D_u1>D_u2>͐>D_un (10) ࡇࡢ⨨᥮ࢆ⾜࠺㛵ᩘࢆO₁࡜ࡋ㸪u=O₁[r]ࡢࡼ࠺࡟⾲

グࡍࡿ㸬ࡲࡓ㸪ㄗࡾゞṇ➢ྕࡢ᳨ᰝ⾜ิ H ࡢิ࡟

ᑐࡋ࡚ࡶྠᵝ࡟⨨᥮O₁ࢆ⾜࠸㸪᪂ࡓ࡞᳨ᰝ⾜ิH^ᇱ㸻 O₁[H]㸻ሺhԢଵǡ hԢଶǡ ڮ ǡhԢ௡ሻࢆᚓࡿ㸬ࡓࡔࡋ㸪hԢ௜ࡣHԢࡢ i␒┠ࡢิ࣋ࢡࢺࣝࢆ⾲ࡍ㸬ࡲࡓ㸪h′௜ࡣu_iࡢಙ㢗ᗘ D_ui࡟ᑐᛂࡍࡿࡢ࡛㸪ಙ㢗ᗘD_uiࢆhԢ௜࡟ᑐᛂࡍࡿಙ㢗 ᗘ࡜࿧ࡪ㸬

ḟ࡟᳨ᰝ⾜ิࡴ^ᇱ࡟ᑐࡋ࡚㸪⾜᧯సࢆ⾜࠸㸪⤌⧊➢

ྕ࡟ᑐᛂࡍࡿᶆ‽ᙧ࡟ࡍࡿ㸬ࡇࡢ࡜ࡁ㸪ࡴԢࡢಙ㢗ᗘ ࡢప࠸n-kิࡀ1ḟ⊂❧࡛ࡣ࡞࠸࡞ࡽࡤ㸪ᶆ‽ᙧ࡟

࡛ࡁ࡞࠸ࡢ࡛㸪ࡴԢࡢิ࣋ࢡࢺࣝ࠿ࡽᑐᛂࡍࡿಙ㢗ᗘ ࡀప࠸㡰࡟1ḟ⊂❧࡞n-kิࢆ㑅ࡧฟࡍ㸬ࡇࡢn-k

ิࢆಙ㢗ᗘࡀ㝆㡰࡟࡞ࡿࡼ࠺࡟ิ⨨᥮ࡋࡓࡶࡢࢆ

᪂ࡋ࠸᳨ᰝ⾜ิHԢԢࡢᚋࢁࡢn-kิ࡜ࡋ㸪᳨ᰝ⾜ิHԢ ࡢṧࡾࡢkิ࡟ᑐࡋ࡚ࡣ㸪ิ࣋ࢡࢺࣝ࡟ᑐᛂࡍࡿಙ 㢗ᗘࡀ㝆㡰࡟࡞ࡿࡼ࠺ิ࣋ࢡࢺࣝࢆ⨨᥮ࡋࡓࡶࡢ

ࢆ᪂ࡋ࠸᳨ᰝ⾜ิࡴԢԢࡢጞࡵࡢ k ิ࡜ࡍࡿ㸬௨ୖࡢ

⨨ ᥮ ࢆ ⾜ ࠺ 㛵 ᩘ ࢆO₂ ࡜ ࡍ ࡿ ࡜ 㸪HԢԢ㸻O₂[HԢ]㸻 O₂[O₁[H]]㸻ሺhԢԢଵǡ hԢԢଶǡ ڮ ǡhԢԢ௡ሻ࡜࡞ࡿ㸬ྠᵝ࡟㸪u࡟ ᑐࡋ࡚ࡶ⨨᥮O₂ࢆ⾜࠸㸪ࡑࢀ࡟ࡼࡗ࡚ᚓࡽࢀࡓ᪂ࡓ

࡞⣔ิࢆz㸻O₂[u]㸻O₂[O₁[r]]㸻(z₁,z₂, ͐,z_k,z_k+1, ͐,z_n)

࡜ࡍࡿ㸬ࡇࡢ࡜ࡁ㸪zࡢྛࣅࢵࢺࡢಙ㢗ᗘ࡟ᑐࡋ࡚

ḟᘧࡀᡂࡾ❧ࡘ㸬

D_z1>D_z2>͐>D_zk D_zk+1>D_zk+2>͐>D_zn

ḟ࡟㸪ᚓࡽࢀࡓࡴ^ᇱᇱ࡟ᑐࡋ࡚⾜᧯సࢆ⾜࠸㸪⤌⧊

➢ྕ࡟ᑐᛂࡍࡿᶆ‽ᙧ࡟᳨ᰝ⾜ิH₁ࢆᚓࡿ㸬ࡇࡇ

࡛H₁ࡣ

>> @

»»

»»

»

¼ º

««

««

«

¬ ª

1 0 0

0 1 0

0 0 1

, , ,

, 2 , 2 , 2

, 1 , 1 , 1 l

k k k k n

p p p

p p p

p p p I

P

H (12)

࡜࡞ࡿ㸬ࡓࡔࡋ㸪pࡣk™kࡢ⾜ิ㸪I_n-kࡣ(n-k)™(n-k) ࡢ༢఩⾜ิ࡛࠶ࡿ㸬

ḟ࡟zࡢ◳ุᐃ್a = (a₁,a₂,͐,a_n)ࢆḟᘧ࡛ᐃ⩏ࡍ

ࡿ㸬

¯¯®

­

d

! 0 for , 1

0 for , 0

i i

i z

a z

(13)

a ࡜ H_lࡢ㌿⨨ H_l^T࡜ࡢ✚࡟ࡼࡾ㸪ࢩࣥࢻ࣮࣒ࣟ s

=aH_l^T=(s₁,s₂,͐,s_n-k)ࢆᚓࡿ㸬᭦࡟㸪a࡜sࢆ⏝࠸࡚➢

ྕㄒࢊ_௖଴^ᇱ ࢆḟᘧ࡟ࡼࡾᚓࡿ㸬

ࢊ_௖଴^ᇱ = (a₁,a₂,͐,a_k,a₁+s₁,a₂+s₂,͐,a_n+s_n-k) (14) ࡇࡢ᫬㸪H_lࡣᶆ‽ᙧࡢ᳨ᰝ⾜ิ࡛࠶ࡿࡢ࡛㸪➢ྕㄒ

ࢊ_௖଴^ᇱ ࡢࢩࣥࢻ࣮࣒ࣟࡣ࢙Ԣ₀= ࢊ_௖଴^ᇱ H_l^T =0࡜࡞ࡿ㸪᭱ᚋ࡟

OOࡢ ㏫ ⨨ ᥮OOࢆ ⏝ ࠸ ࡚ 㸪 ᚟ ྕ ㄒ d_c0㸻 O[Oࢊ_௖଴^ᇱ ]]ࢆᚓࡿ㸬ࡇࡢ࡜ࡁ㸪d_c0ࡢࢩࣥࢻ࣮࣒ࣟ

࢙₀㸻d_c0H^T㸻(s₀₁,s₀₂,͐,s_0n-k)ࡣ࢙Ԣ₀㸻0 ࡛࠶ࡿࡢ࡛㸪ࢊ_௖଴^ᇱ

࡟ᑐࡋ࡚㏫⨨᥮OOࢆ⾜ࡗ࡚ࡶࢩࣥࢻ࣮࣒ࣟࡣ ኚ໬ࡏࡎ㸪࢙₀㸻0࡜࡞ࡿ㸪ࡋࡓࡀࡗ࡚㸪d_c0ࡣ➢ྕㄒ

࡛࠶ࡾ㸪ཷಙ⣔ิࡢ୰࡛ಙ㢗ᗘࡢప࠸n-k [bit]࡟ᑐ ࡋ࡚ㄗࡾゞṇࢆ⾜ࡗࡓࡶࡢ࡟࡞ࡗ࡚࠸ࡿ㸬௨ୖࡢฎ

⌮ࢆ㡰ᗎ⤫ィ㔞᚟ྕࡢOrder-0ࡢฎ⌮࡜࿧ࡪ㸬⁹⁾㸬

Order-lࡢ㡰ᗎ⤫ィ㔞᚟ྕ

Order-0ࡢฎ⌮࡛ࡣಙ㢗ᗘࡢ㧗࠸k[bit]ࡢ୰࡟ㄗࡾ

ࡀⓎ⏕ࡋ࡚࠸ࡿሙྜ㸪ゞṇ࡛ࡁ࡞࠸ࡢ࡛㸪ಙ㢗ᗘࡢ

㧗࠸ k[bit]ࡢ⠊ᅖ࠿ࡽࡶㄗࡾࡀⓎ⏕ࡋ࡚࠸ࡿ࡜௬ᐃ

ࡋ࡚ゞṇࢆ⾜࠺㸬ࡇࡢࡼ࠺࡞ฎ⌮ࢆ㡰ᗎ⤫ィ㔞᚟ྕ

ࡢOrder-l㸦l > 1㸧ࡢฎ⌮࡜࿧ࡪ㸬Fig. 9࡟㡰ᗎ⤫ィ 㔞᚟ྕࢆ⏝࠸ࡓ㏦ಙㄒೃ⿵⏕ᡂࡢὶࢀࢆ♧ࡍ㸬 Order- l㸦l > 1㸧ࡢฎ⌮࡛ࡣ㸪ಙ㢗ᗘࡢ㧗࠸k [bit] ࡢ

⠊ᅖ࡟௬ࡢㄗࡾ⣔ิe₀ = (e₀₁, e₀₂,͐, e_0n)ࢆ௜ຍࡍࡿ㸬 ௬ࡢㄗࡾ⣔ิe₀ࢆ㛗ࡉkࡢ⣔ิe^k = (e^k₁, e^k₂,͐, e^k_k)

ࢆ⏝࠸࡚e₀= (e^k ,0,0,͐,0) = (e^k₁, e^k₂,͐, e^k_k,0,0,͐,0)࡜

ࡍࡿ㸬ḟ࡟ࢩࣥࢻ࣮࣒ࣟs_l= (s_{l 1}, s_{l 2},͐, s_{l n-k})ࢆs_l= e₀H_l^T࡟ࡼࡾィ⟬ࡍࡿ㸬➢ྕㄒ࡟௜ຍࡍࡿㄗࡾ⣔ิ

ࢆe₁ = (e^k , s_l)= (e^k₁, e^k₂,͐, e^k_k, s_{l 1}, s_{l 2},͐, s_{l n-k})࡜ࡋ㸪 ᪂ࡓ࡞➢ྕㄒࢊ_௖௟^ᇱ ࢆࢊ_௖௟^ᇱ 㸻㸻ࢊ_௖଴^ᇱ +e₁࡜ࡋ࡚⏕ᡂࡍࡿ㸬ㄗ

ࡾ⣔ิe₁ࢆຍ࠼ࡓࡇ࡜࡛ಙ㢗ᗘࡢ㧗࠸k [bit]ࡢ⠊ᅖ

࡟௬ᐃࡋࡓㄗࡾࢆゞṇࡋࡓ➢ྕㄒࢊ_௖௟^ᇱ ࡜࡞ࡿ㸬ࢊ_௖௟^ᇱ ࢆ

㏫⨨᥮ࡋࢊ_௖௟㸻O

[O[ࢊ_௖௟^ᇱ ]]ࢆᚓࡿ㸬e^kࡢ᭦᪂࡟ࡼ

ࡾㄗࡾ⣔ิࡢ᭦᪂ࢆ⾜ࡗ࡚࠸ࡃ㸬ࡓࡔࡋ㸪ㄗࡾ⣔ิ

e^kࡢ᭦᪂ࡣTable 1ࡢࡼ࠺࡟࡞ࡿ㸬௨ᚋྠᵝࡢ᚟ྕ

ฎ⌮ࢆ㸪タᐃࡋࡓOrderᩘࡢe^kࡣ

ࢋ^௞ ൌ ሺͳǡͳǡ ڮ ǡͳᇣᇧᇤᇧᇥ

௟

ǡ ͲǡͲǡ ڮ ǡͲሻ (15)

࡜࡞ࡿࡲ࡛ㄗࡾ⣔ิࢆ᭦᪂ࡋ㸪㏦ಙ➢ྕㄒೃ⿵ࢆ⏕

ᡂࡋ࡚࠸ࡃ㸬ࡇࡢࡼ࠺࡞ฎ⌮ࢆ㡰ᗎ⤫ィ㔞᚟ྕࡢ Order- l㸦l > 1㸧ࡢฎ⌮࡜࿧ࡪ㸬ࡲࡓ㸪e^kࡢࣁ࣑ࣥࢢ

㔜ࡳࡀi㸦lӍiӍ1㸧ࡢ᫬ࡢ᚟ྕฎ⌮ࢆ㸪Order-lࡢ᚟

ྕฎ⌮ࡢPhase-i࡜࿧ࡪ⁹⁾㸬

Table 1. Error sequence

Phase-1 Phase-2 ͐ Phase-i

(0,͐,0,0,0,1)

(0,͐,0,0,1,0)

(0,͐,1,0,0,0)

(1,0,0,0,͐,0)

(0,͐,0,0,1,1)

(0,͐,0,1,0,1)

(0,͐,0,1,1,0)

(1,1,0,0,͐,0)

͐

͐

͐

͐

(0,͐,0,0,1,1,1, ͐,1)

(0,͐,0,1,0,1,1, ͐,1)

(0,͐,0,1,1,0, 1,͐,1)

(1,1,1, ͐,1,0,0,͐,0)

(11)

䢧 䢧 䢧

i i-1

i-2 i

Fig. 9. Generation of candidates by the ordered statistics decoding for the quasi-maximum likelihood detection.

ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ

ࢩ࣑࣮ࣗࣞࢩࣙࣥࢩࢫࢸ࣒

ᥦ᱌᪉ᘧࡢ᭷ຠᛶࢆホ౯ࡍࡿࡓࡵ࡟ィ⟬ᶵࢩ࣑

࣮ࣗࣞࢩࣙࣥࢆ⾜࠺㸬➢ྕ໬ MC-CDMA ࡢࢩ࣑ࣗ

࣮ࣞࢩࣙࣥࣔࢹࣝ࡟ࡣFig. 4ࡢ㏦ಙᶵࢆ⏝࠸㸪Fig. 5 ࡢㄗࡾゞṇ᚟ྕࢆಶู࡟⾜࠺ཷಙᶵࡢࣔࢹࣝ࡜㸪

Fig. 6ࡢㄗࡾゞṇ᚟ྕ࡜࣐ࣝࢳ࣮ࣘࢨ᳨ฟࢆ୍య໬

ฎ⌮ࡍࡿཷಙᶵࡢࣔࢹࣝࢆ⏝࠸ࡿ㸬

㏦ಙᶵ࡛ࡣBCH➢ྕ໬ࢆ⾜࠸PSKኚㄪࡉࢀࡓࢹ

࣮ࢱࢆ⏝࠸࡚ MC-CDMA ಙྕࢆ㏦ಙࡍࡿ㸬୍య໬

ฎ⌮ࡍࡿཷಙᶵ࡛ࡣ㸪ཷಙಙྕ࠿ࡽMMSECࢆ⏝࠸

ࡓ᚟ㄪࢹ࣮ࢱࢆ௬ุᐃࢹ࣮ࢱ࡜ࡋ࡚᚟ྕࢆ⾜࠺㸬ࡇ ࡢ௬ุᐃࢹ࣮ࢱࢆ⏝࠸࡚࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾ

ゞṇ᚟ྕࢆ୍య໬ฎ⌮ࡍࡿ‽᭱ᑬ᚟ྕࢆ⾜࠺㸬୍య

໬ฎ⌮࡟࠾ࡅࡿ㏦ಙㄒೃ⿵ࡢ⏕ᡂ࡟ࡣ㸪ࢸ࣮ࣈࣝཧ

↷᚟ྕ㸪㡰ᗎ⤫ィ㔞᚟ྕࡢྛᡭἲࢆ⏝࠸࡚ࡑࢀࡒࢀ

⾜࠺㸬࡞࠾㸪ࢩ࣑࣮ࣗࣞࢩࣙࣥ࡟࠾࠸࡚㸪MMSEC ࡢ㔜ࡳ௜ࡅಀᩘࢆỴᐃࡍࡿ㝿࡟⏝࠸ࡿ㞧㡢ࡢศᩓ ࡣཷಙഃ࡛᪤▱࡜ࡍࡿ㸬ྛ᪉ᘧࡢ E_b/N₀㸦᝟ሗ᚟ㄪ ᚋࡢ 1 ࣅࢵࢺ࠶ࡓࡾࡢಙྕᑐ㞧㡢㟁ຊẚ㸧ᑐ BER

≉ᛶࢆィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ࡟ࡼࡗ࡚ồࡵ㸪ホ౯

ࢆ⾜ࡗࡓ㸬Table 2࡟ࢩ࣑࣮ࣗࣞࢩࣙࣥㅖඖࢆ♧ࡍ㸬

࡞࠾㸪ᮏ◊✲࡛ࡣࢥ࣮ࢻ㛫ᖸ΅ࡢᙳ㡪࡟ᑐࡍࡿຠᯝ ࡢ᭷ຠᛶࢆ☜ㄆࡍࡿࡓࡵ㸪AWGN ఏ㏦㊰࡛ࡣ㸪㐜 ᘏἼࡀ⏕ࡌࡿ⎔ቃࢆ᝿ᐃࡍࡿ㸬┤᥋Ἴ࡜㐜ᘏἼ࡛ࡣ

఩┦ࡀࣛࣥࢲ࣒࡟␗࡞ࡿࡶࡢ࡜ࡍࡿ㸬ࢩ࣑࣮ࣗࣞࢩ

ࣙࣥㅖඖ࡟࠾࠸࡚㸪➢ྕ㛗n㸪᝟ሗ㛗kࡢBCH➢

ྕࢆBCH(n,k)࡜⾲ࡍ㸬

ࡲࡓ㸪QPSKኚㄪࢆ⾜࠺ሙྜ࡟ࡣወᩘࣅࢵࢺn࡜

࡞ࡿ1➢ྕㄒ࡟෕㛗࡞1ࣅࢵࢺࢆຍ࠼ࡓࢹ࣮ࢱ࡛ከ 㔜 ࡋ ࡚ ࠸ ࡿ 㸬 ࡼ ࡗ ࡚ ከ 㔜 ᩘ ࡣ(n+1)/2 ࡜ ࡞ ࡿ

MC-CDMAಙྕࢆ⏕ᡂࡋ࡚࠸ࡿ㸬

Table 2. Simulation parameters Information modulation BPSK㸪QPSK

Coding BCH(31,21)㸪BCH(15,11) MC-CDMA

Subcarriers㸸32 Spreading factor㸸32 Spread code㸸Walsh code

Channel

AWGN㸪Rayleigh fading Number of delay wave㸸1 Delay time㸸1sample DUR㸸4 dB

MC-CDMA demodulation MMSEC

Channel estimation Pilot symbol

ࢩ࣑࣮ࣗࣞࢩࣙࣥ⤖ᯝ

Fig. 10㸪Fig. 11㸪Fig. 18㸪Fig. 19࡟ࡣ➢ྕ໬ࢆ⾜

ࢃ࡞࠸MC-CDMAࢩࢫࢸ࣒࡟࠾ࡅࡿBER≉ᛶࢆ♧

ࡋ࡚࠸ࡿ㸬Fig. 10㸪Fig. 11ࡣBPSKኚㄪ㸪Fig. 10㸪 Fig. 11ࡣQPSKኚㄪ࡛࠶ࡿ㸬Fig. 10㸪Fig. 18࡛ࡣከ 㔜ᩘቑຍ࡟క࠺ࢥ࣮ࢻ㛫ᖸ΅ࡢᙳ㡪ࢆ♧ࡍ㸬Fig. 11㸪

Fig. 19 ࡟ࡣ1 ࣅࢵࢺኚ᥮࡟ࡼࡿ‽᭱ᑬ᳨ฟࢆ⾜ࡗ

ࡓ࡜ࡁࡢ BER ≉ᛶᨵၿຠᯝࡢᅗ࡛࠶ࡿ㸬➢ྕ໬

MC-CDMA ࡟ྛ᪉ᘧࢆ㐺⏝ࡋࡓ BPSK ኚㄪ᫬ࡢ⤖

ᯝࢆFig. 12㹼17 ࡟ࡲ࡜ࡵ㸪QPSKኚㄪ᫬ࡢ⤖ᯝࢆ

Fig. 20㹼25࡟ࡲ࡜ࡵࡿ㸬Fig. 12㸪Fig. 15㸪Fig. 20㸪

Fig. 23࡟ࡣ Fig. 5ࡢཷಙᶵࢆ⏝࠸࡚ㄗࡾゞṇ᚟ྕ

ࢆ ಶ ู ࡟ ⾜ ࡗ ࡓ ሙ ྜ ࡜ 㸪 ➢ ྕ ໬ ࢆ ⾜ ࢃ ࡞ ࠸ MC-CDMAࡢE_b/N₀ᑐBER≉ᛶ࡛࠶ࡿ㸬Fig. 12㸪 Fig.

20ࡣAWGN⎔ቃ㸪Fig. 15㸪Fig. 23ࡣࣞ࢖࣮ࣜࣇ࢙

࣮ࢪࣥࢢ⎔ቃ࡛ࡢE_b/N₀ᑐBER≉ᛶ࡛࠶ࡿ㸬 Fig. 13㸪Fig. 14㸪Fig. 16㸪Fig. 17㸪Fig. 21㸪Fig. 22㸪

Fig. 24㸪Fig. 25࡟ࡣ㸪ㄗࡾゞṇ᚟ྕࢆಶู࡟⾜ࡗࡓ

ሙྜ࡜㸪㏦ಙ➢ྕㄒೃ⿵ࢆࡑࢀࡒࢀࢸ࣮ࣈࣝཧ↷᚟

ྕἲ࡜㡰ᗎ⤫ィ㔞᚟ྕἲࢆ⏝࠸࡚⏕ᡂࡋࡓྛ‽᭱

ᑬ᚟ྕ᪉ᘧࡢE_b/N₀ᑐBER≉ᛶࢆ♧ࡍ㸬Fig. 13㸪Fig.

14㸪Fig. 21㸪Fig. 22ࡣ AWGN⎔ቃ࡟࠾ࡅࡿE_b/N₀ ᑐBER≉ᛶ࡛࠶ࡾ㸪Fig. 16㸪Fig. 17㸪Fig. 24㸪Fig. 25 ࡣࣞ࢖࣮ࣜࣇ࢙࣮ࢪࣥࢢ⎔ቃ࡟࠾ࡅࡿE_b/N₀ᑐBER

≉ᛶࢆ♧ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪Table 3࡜Table 4࡟ࡣྛ

‽᭱ᑬ᳨ฟἲ࡛⏕ᡂࡍࡿ㏦ಙㄒೃ⿵ᩘࢆ♧ࡍ㸬

MC-CDMA demodulation data

Candidates for transmitted code Calculation of

LLR Sort by using LLR

Syndrome calculation Permutation of H

Transformed into the original data position

O2-1эO1-1

Demodulation

In case of Order-l(l≥1) Add to the virtual Error sequences to the range of high reliability bits

Error sequences Parity check

matrix H

Sort in order of LLR values : O1

Permuted by using O1

Transformed into canonical form O2 Sort according

to O2

O1 O2

H′′

MC-CDMA demodulation data

H′′

Parity check matrix H

Sorted data

ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ

Table 3. The number of candidates for 1-bit conversion method number of candidates 1-bit

conversion method

BPSK Multiplexing + 1

QPSK Twice the number of Multiplexing + 1

Table 4. The number of candidates for Joint Multiuser Detection and Decoding methods

number of candidates BCH

(15,11)

BCH (31,21) Table-aided

decoding dD

3 36 5

4 120 31~40

5 309 187~202

Ordered statistics decoding

Order

0 1 1

1 12 22

2 67 231

3 232 1562

Fig. 10. The influence of inter-code interference for MC-CDMA over AWGN channel

Fig. 11. Performance of BER versus Eb/N0 in quasi-maximum likelihood estimation using 1-bit conversion method

over AWGN channel

Fig. 12. BER performance of MC-CDMA and coded MC-CDMA in AWGN channel (BPSK)

Fig. 13. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in AWGN channel

(BPSK BCH(n,k)=(15,11) , multiplexing 15)

Fig. 14. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in AWGN channel

(BPSK ,BCH(n,k)=(31,21) , multiplexing=31)

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

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^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇 䣔

䢢

䢢

䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢴 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢶 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢴

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

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䢳䢲

^䢯䢶

䢳䢲

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䢳䢲

^䢯䢴

䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢴 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢶 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢴

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

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䢳䢲

^䢯䢶

䢳䢲

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䢳䢲

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䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢳䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢵䢳䢮䢴䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢳䢫 䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢷䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢳䢷䢮䢳䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢷䢫

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

^䢯䢷

䢳䢲

^䢯䢶

䢳䢲

^䢯䢵

䢳䢲

^䢯䢴

䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴䢢 䣑䣴䣦䣧䣴䢢䢵䢢

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

^䢯䢷

䢳䢲

^䢯䢶

䢳䢲

^䢯䢵

䢳䢲

^䢯䢴

䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳䢢 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵 BPSK

BPSK BPSK

BPSK

BPSK

Fig. 15. BER performance of MC-CDMA and coded MC-CDMA inrayleigh fading channel (BPSK)

Fig. 16. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in rayleigh fading channel

(BPSK BCH(n,k)=(15,11) , multiplexing 15)

Fig. 17. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in rayleigh fading channel

(BPSK ,BCH(n,k)=(31,21) , multiplexing=31)

Fig. 18. The influence of inter-code interference for MC-CDMA over AWGN channel

Fig. 19. Performance of BER versus Eb/N0 in quasi-maximum likelihood estimation using 1-bit conversion method

over AWGN channel

Fig. 20. BER performance of MC-CDMA and coded MC-CDMA in AWGN channel (QPSK)

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢳䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢵䢳䢮䢴䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢳䢫 䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢷䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢳䢷䢮䢳䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢷䢫

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

^䢯䢷

䢳䢲

^䢯䢶

䢳䢲

^䢯䢵

䢳䢲

^䢯䢴

䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇 䣔

䢢

䢢

䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢴 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢶 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲

^䢯䢷

䢳䢲

^䢯䢶

䢳䢲

^䢯䢵

䢳䢲

^䢯䢴

䢳䢲

^䢯䢳

䢳䢲

^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢴 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢶 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸 䣯䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢵䢴

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢵䢳䢮䢴䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸䢫 䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢳䢷䢮䢳䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺䢫 BPSK

BPSK

BPSK QPSK

QPSK QPSK

Fig. 21. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in AWGN channel

(QPSK BCH(n,k)=(15,11) , multiplexing 8)

Fig. 22. BER performance of joint multiuser detection and decoding

method for coded MC-CDMA in AWGN channel (QPSK BCH(n,k)=(31,21) , multiplexing 16)

Fig. 23. BER performance of MC-CDMA and coded MC-CDMA inrayleigh fading channel. (QPSK)

Fig. 24. BER performance of joint multiuser detection and decoding

method for coded MC-CDMA in rayleigh fading channel (QPSK BCH(n,k)=(15,11) , multiplexing 8)

Fig. 25. BER performance of joint multiuser detection and decoding method for coded MC-CDMA in rayleigh fading channel

(QPSK BCH(n,k)=(31,21) , multiplexing 16)

Fig. 10㸪Fig. 11ࢆẚ㍑ࡍࡿ࡜㸪1ࣅࢵࢺኚ᥮࡟ࡼࡿ

‽᭱ᑬ᳨ฟ࡛ࡣከ㔜ᩘࡀ8ࡲ࡛ࡣ㸪ࢥ࣮ࢻ㛫ᖸ΅ࡢ ᙳ㡪ࢆ࡯ࡰ㝖ཤࡋ࡛ࡁ࡚࠸ࡿࡀ㸪ከ㔜ᩘ16௨ୖࡢ ሙྜࡣᖸ΅ࡢᙳ㡪ࡀṧࡾ㸪≉ᛶᨵၿࡢຠᯝࡣᑠࡉࡃ

࡞ࡗ࡚࠸ࡿ㸬Fig. 13㸪Fig. 14࠿ࡽࡣ࣐ࣝࢳ࣮ࣘࢨ᳨

ฟ࡜ㄗࡾゞṇ᚟ྕࡢ୍య໬ฎ⌮ࢆ㐺⏝ࡋࡓ᪉ࡀಶ

ู࡟ㄗࡾゞṇࢆ⾜࠺ࡼࡾࡶ BER≉ᛶࢆᨵၿ࡛ࡁࡿ

ࡢࡀ☜ㄆ࡛ࡁ㸪࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࡢ

୍య໬ฎ⌮ࡀຠᯝ࡛࠶ࡿ࡜ゝ࠼ࡿ㸬ࡲࡓ㸪ᥦ᱌᪉ᘧ ࡣ᭱ࡶBER ≉ᛶࢆᨵၿ࡛ࡁ࡚࠾ࡾ㸪ࢥ࣮ࢻ㛫ᖸ΅

࡟ࡼࡿຎ໬ࢆᢚ࠼ࡿࡢ࡟᪤Ꮡࡢࢸ࣮ࣈࣝཧ↷᚟ྕ

᪉ᘧࡼࡾࡶຠᯝⓗ࡛࠶ࡿ࡜ゝ࠼ࡿ㸬

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䣦䣆䢿䢵 䣖䣣䣤䣮䣧䢢䣦䣆䢿䢶 䣖䣣䣤䣮䣧䢢䣦䣆䢿䢷 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢凚䣦䣆䢿䢵凛 䣖䣣䣤䣮䣧䢢凚䣦䣆䢿䢶凛 䣖䣣䣤䣮䣧凚䢢䣦䣆䢿䢷凛 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢵䢳䢮䢴䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢳䢸䢫 䣏䣅䢯䣅䣆䣏䣃傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺䢫

䣅䣱䣦䣧䣦䢢䣏䣅䢯䣅䣆䣏䣃䢪䢳䢷䢮䢳䢳䢫傍䢪䣏䣷䣮䣶䣫䣲䣮䣧䣺䣫䣰䣩䢢䢺䢫

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵

䢲 䢷 䢳䢲 䢳䢷 䢴䢲 䢴䢷

䢳䢲^䢯䢷 䢳䢲^䢯䢶 䢳䢲^䢯䢵 䢳䢲^䢯䢴 䢳䢲^䢯䢳 䢳䢲^䢲

䣇䣤䢱䣐䣱䣝䣦䣄䣟

䣄䣇䣔

䢢

䢢

䣕䣧䣴䣫䣣䣮䢢䣦䣧䣥䣱䣦䣫䣰䣩 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢵䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢶䢫 䣖䣣䣤䣮䣧䢢䢪䣦䣆䢢䢿䢢䢷䢫 䣑䣴䣦䣧䣴䢢䢲 䣑䣴䣦䣧䣴䢢䢳 䣑䣴䣦䣧䣴䢢䢴 䣑䣴䣦䣧䣴䢢䢵 QPSK

QPSK

QPSK

QPSK

QPSK

ࣞ࢖࣮ࣜࣇ࢙࣮ࢪࣥࢢ⎔ቃࡢ⤖ᯝ࡛࠶ࡿ Fig. 16 ࡢከ㔜ᩘࡀ15ࡢሙྜ࡟ࡣ㸪ᥦ᱌᪉ᘧࡢOreder-1௨

ୖ࡜ࢸ࣮ࣈࣝཧ↷᚟ྕἲࡢ඲ d_Dࡢሙྜ࡜➼ࡋ࠸

BER≉ᛶࡀ⾲ࢀ࡚࠸ࡿ㸬ࡋ࠿ࡋ㸪ከ㔜ᩘ31ࡢFig. 17 ࡢሙྜ࡟ࡣᥦ᱌᪉ᘧࡢOrder-1ࡢẁ㝵࡛ࢸ࣮ࣈࣝཧ

↷᚟ྕἲࡢd_D=5࡜ྠ➼ࡢBER≉ᛶࡀᚓࡽࢀ࡚࠸ࡿ㸬 ࡇࡢྠ➼ࡢ≉ᛶࢆᚓࡿࡓࡵࡢೃ⿵ᩘࢆ㸪Table 4 ࢆ

⏝࠸࡚ẚ㍑ࡍࡿ࡜ࢸ࣮ࣈࣝཧ↷᚟ྕἲࡢd_D=5࡛ࡣ 187~202ಶ࡞ࡢ࡟ᑐࡋ㸪ᥦ᱌᪉ᘧࡢOrder-1࡛ࡣ22

࡛࠶ࡾ㸪ᥦ᱌᪉ᘧࡢಙ㢗ᗘࢆ⏝࠸ࡓೃ⿵ࡢ⏕ᡂἲࡀ

ຠᯝⓗࡔ࡜࠸࠼ࡿ㸬ࡲࡓ㸪ࢸ࣮ࣈࣝཧ↷᚟ྕἲ࡛ࡼ

ࡾ≉ᛶᨵၿࡍࡿࡓࡵ࡟ࡣࡼࡾከࡃࡢೃ⿵ࢆಖᏑࡋ

࡚࠾ࡃᚲせࡀ࠶ࡾ㸪࣓ࣔࣜ㔞ၥ㢟ࡢࡓࡵᅔ㞴࡛࠶ࡿ㸬 ࡋ࠿ࡋ㸪ᥦ᱌᪉ᘧ࡛ࡣOrderࢆ࠶ࡆࡿࡇ࡜࡛ࡉࡽ࡟

BER≉ᛶᨵၿࡉࢀ࡚࠸ࡿ㸬

Fig. 18㹼Fig. 25 ࡣ QPSK ኚㄪࡢሙྜ࡛࠶ࡾ㸪 BPSKኚㄪࡢሙྜ࡜ྠᵝࡢࢩ࣑࣮ࣗࣞࢩࣙࣥࢆࡑࢀ

ࡒࢀ⾜ࡗࡓࡶࡢ࡛࠶ࡿࡀ㸪➢ྕ໬ MC-CDMA ࡟࠾

࠸࡚ྠࡌ➢ྕ㛗ࢆ⏝࠸ࡓሙྜ㸪BPSKኚㄪࡢࢩ࣑ࣗ

࣮ࣞࢩࣙࣥ࡜ẚ࡭ከ㔜ᩘࡣ༙ῶࡋࡓࡶࡢ࡛࠶ࡿ㸬 QPSKኚㄪࡢ⤖ᯝ࠿ࡽࡶ㸪AWGN⎔ቃ࡜ࣞ࢖࣮ࣜࣇ

࢙࣮ࢪࣥࢢ⎔ቃ࡟࠾࠸࡚㸪BPSKኚㄪ⤖ᯝ࡜ྠᵝ࡟

ᥦ᱌᪉ᘧࡀ᭱ࡶBER ≉ᛶࢆᨵၿࡋ࡚࠸ࡿ࡜࠸࠼ࡿ㸬

ࡼࡗ࡚㸪4.1⠇࡛㏙࡭ࡓQPSKኚㄪ᫬࡟࠾ࡅࡿLLR ィ⟬ࡢ⡆␎໬ࢆ⾜ࡗ࡚ࡶ㸪ᥦ᱌᪉ᘧࡣၥ㢟࡞࠸ࡇ࡜

ࡀ☜ㄆ࡛ࡁࡿ㸬

ࡲ࡜ࡵ

ᮏ◊✲࡛ࡣ㸪BCH ➢ྕ࡟ࡼࡿㄗࡾゞṇ➢ྕ໬ࢆ

㐺⏝ࡋࡓ MC-CDMA ࢩࢫࢸ࣒࡟࠾࠸࡚㸪㡰ᗎ⤫ィ

㔞᚟ྕࢆ⏝࠸࡚㏦ಙ➢ྕㄒೃ⿵ࢆ⏕ᡂࡋ㸪࣐ࣝࢳࣘ

࣮ࢨ᳨ฟ࡜ㄗࡾゞṇ᚟ྕࢆ୍య໬ฎ⌮ࡋ࡚⾜࠺‽

᭱ᑬ᚟ྕ᪉ᘧࢆᥦ᱌ࡋࡓ㸬ィ⟬ᶵࢩ࣑࣮ࣗࣞࢩࣙࣥ

࡛ࡣ1ࣅࢵࢺኚ᥮࡟ࡼࡿ‽᭱ᑬ᳨ฟ࡛ࡢBER≉ᛶ ᨵၿࢆㄪ࡭㸪ࢸ࣮ࣈࣝཧ↷᚟ྕἲࢆ⏝࠸ࡓ‽᭱ᑬ᚟

ྕ᪉ᘧ࡜ᥦ᱌᪉ᘧࡢ BER≉ᛶẚ㍑ࢆ⾜࠸ホ౯ࢆ⾜

ࡗࡓ㸬ࢸ࣮ࣈࣝཧ↷᚟ྕἲࢆ⏝࠸ࡓ‽᭱ᑬ᚟ྕ᪉ᘧ ࡣᥦ᱌᪉ᘧ࡜ྠᵝ࡟࣐ࣝࢳ࣮ࣘࢨ᳨ฟ࡜ㄗࡾゞṇ

᚟ྕࢆ୍య໬ฎ⌮ࡍࡿ᪉ᘧ࡛࠶ࡿ㸬ࢩ࣑࣮ࣗࣞࢩࣙ

ࣥ࡟ࡼࡿᐃ㔞ⓗホ౯ࡢ⤖ᯝ㸪ᥦ᱌᪉ᘧࡀ᭱ࡶ BER

≉ᛶࢆᨵၿࡍࡿࡇ࡜ࡀฟ᮶ࡓ㸬

ࢸ࣮ࣈࣝཧ↷᚟ྕࡢᡭἲࢆ⏝࠸ࡓ᪉ᘧ࡛㸪BER

≉ᛶࢆࡉࡽ࡟ᨵၿࡍࡿ࡟ࡣ㸪㏦ಙ➢ྕㄒೃ⿵⏕ᡂ࡟

ᚲせ࡜ࡍࡿࢸ࣮ࣈࣝಖᏑࡢ࣓ࣔࣜᐜ㔞ࡀቑ኱ࡋ㸪㐺

⏝ࡀᅔ㞴࡜࡞ࡿ㸬ࡼࡗ࡚㸪㏦ಙㄒೃ⿵ᩘࡀከࡃ࡞ࡿ

➢ྕ㛗ࡀ㛗࠸ሙྜ࡟ࡣ㸪࣓ࣔࣜ㔞ၥ㢟ࡢ㉳ࡇࡽ࡞࠸

㡰ᗎ⤫ィ㔞᚟ྕࢆࡢᡭἲࢆ⏝࠸ࡓᥦ᱌᪉ᘧࡢ᭷ຠ

ᛶࡀ㧗ࡃ࡞ࡿ࡜⪃࠼ࡽࢀࡿ㸬

ཧ⪃ᩥ⊩

1) S.Hara and R.Prasad, “Overview of multicarrier CDMA, ” IEEE Commun. Mag., pp.126-133, (1997-12).

2)

ᯇᮏ΅㸪ⴠྜ⚽ᶞ㸪

OFDM

ኚㄪ᪉ᘧࡢᛂ⏝

, (

ࢺࣜࢣ

ࢵࣉࢫ♫㸪 2001).

3) A.Chouly, A.Brajal, and S.Jourdan, “Orthogonal multicarrier techniques applied to direct sequence spread spectrum CDMA systems, ” Proc. IEEE GLOBECOM ` 93, pp.1723-1728, (1999-9).

4) S.Hara and R.Prasad, “Design and performance of multicarrier CDMA systems in frequency-selective Rayleigh fading channels, ” IEEE Trans. Veh. Technol., vol.48, pp.1723-1728, (1999-9).

5)

ᰘ ⏣ ㇏ ಙ 㸪 Ύ Ỉ ᓫ அ 㸪 ᒾ ஭ ㄔ ே 㸪 ➲ ᒸ ⚽ ୍ 㸪

“MC-CDMA

᪉ᘧ࡟࠾ࡅࡿ‽᭱ᑬ᥎ᐃࢆ⏝࠸ࡓ࣐ࣝ

ࢳ࣮ࣘࢨཷಙ᪉ᘧࡢ◊✲, ” ಙᏛᢏሗ, RCS2007-156,

pp.133-138,( 2008-1).

6)

༡ⱥᇛ㸪➲ᒸ⚽୍㸪

“

ࣈࣟࢵࢡ➢ྕࡢࢸ࣮ࣈࣝཧ↷

࡟ࡼࡿ㌾ุᐃ᚟ྕἲ

,”

ಙᏛㄽ

(B), vol.J79-B, no.11, pp.728-737(1996-11).

7) M.P.C.Fossorier and S.Lin, “Soft-decision decoding of linear block codes based on ordered statistics,” IEEE Trans. Information Theory, vol.41, no.5, pp.1379-1396, (1995-9).

8)

Ᏺ㔜჆ே㸪⸨஭㞞ᘯ㸪ఀ୹ㄔ㸪ఀ⸨⣫஧㸪

“

ୗࡾᅇ

⥺

MC-CDMA

ࢩࢫࢸ࣒࡟࠾ࡅࡿᑬᗘつ⠊࡟ᇶ࡙ࡃ

M

࢔ࣝࢦࣜࢬ࣒ࢆ⏝࠸ࡓ㏲ḟ᳨ᐃ᪉ᘧ࡜

QRD-M

࢔

ࣝ ࢦ ࣜ ࢬ࣒ ࡜ ࡢẚ ㍑,

”

ಙ Ꮫ ᢏ ሗ

, WBS2005-32, pp.1-6, (2005-10).

9)

ΎỈᓫஅ㸪ᐆ᮶๢ᩥ㸪ᒾ஭ㄔே㸪➲ᒸ⚽୍㸪“㡰ᗎ

⤫ィ㔞࡟ᇶ࡙ࡃ㌾ุᐃ᚟ྕἲࡢィ⟬㔞๐ῶ᪉ἲ

, ”

ಙᏛᢏሗ

, IT2006-113, pp.167-172, (2007-3).