上行PRACH同步过程

1、1.1 上行RACH信道知识1.1.1 上行RACH信道作用上行PRACH信道(Physical Random Access channel)上行随机接入信道,用于UE与网格侧的目标小区进行初始通信的第一条消息内容,其主要作用就是获取目标小区的上行同步.1.1.2 上行RACH信道资源preamble原理手机要取得与UE的上行同步,手机就要在PRACH信道上进行上行同步,然而上行同步是手机通过发送上行同步码来获得的.每个小区都有64个上行同步码,在相同的频率情况下,如果两个小区的上行同步码相同,就会产生严重的上行同步干扰,就无法成功获得上行同步.那Preamble码是由什么产生的呢,协议定义了

2、两种ZC序列(长度分别为839bit和139bit),前面讲PSS的ZC序列的特性时,ZC序列具有很好的自相关性和互相关性.任意两条ZC序列都是相互正交无干扰的.这两种ZC序列的长度为839bit时,其preamble format(Preamble格式)为03, preamble format与小区覆盖半径有关.Preamble format (table 5.7.2-1)指preamble的长度0 3839，序列个数=长度-1=838个4139，序列个数=长度-1=138个Preamble formatTCP(us)Tpreamble-sequence(us)TGT(us)总时长小区覆盖距

3、离(km)01038001001ms1416848005202ms77220316002002ms29368416007203ms1004151339157us1.4Preamble format的格式与小区半径的关系如下:以format0以例:小区半径=min(GT,CP*光速/2=min(103us,100us)*光速/2=100*10(-6)*3*108/2=150000=15km参数ra-PreambleIndex/root-SequenceIndex:preamble的root sequence index索引编号，当PRACH格式为03时，根序列为0837，其838个，分为32个大

4、的逻辑组，每个逻辑索引唯一对应一个物理序列；当PRACH格式为4时，根序列为0137，其138个，分为7个逻辑组, 每个逻辑索引也是唯一对应一个物理序列；由小区配置可用的preamble sequence-index编号，在SIB中广播，一般小区每隔8使用一个根序列（rootsequence重新排序得到逻辑号，考虑preamble的峰均比）, 排序规律：每两个每对相加=839.Preamble逻辑根序列号索引Preamble物理根序列号索引 (按逻辑根序列号升序排列)Format03 (36.211 table5.7.2-4)023129, 710, 140, 699, 120, 719, 2

5、10, 629, 168, 671, 84, 755, 105, 734, 93, 746, 70, 769, 60, 779,2, 837, 1, 838242956, 783, 112, 727, 148, 691303580, 759, 42, 797, 40, 799364135, 804, 73, 766, 146, 693425131, 808, 28, 811, 30, 809, 27, 812, 29, 810526324, 815, 48, 791, 68, 771, 74, 765, 178, 661, 136, 703647586, 753, 78, 761, 43, 7

6、96, 39, 800, 20, 819, 21, 818768995, 744, 202, 637, 190, 649, 181, 658, 137, 702, 125, 714, 151, 68890115217, 622, 128, 711, 142, 697, 122, 717, 203, 636, 118, 721, 110, 729, 89, 750, 103, 736, 61, 778, 55, 784, 15, 824, 14, 82511613512, 827, 23, 816, 34, 805, 37, 802, 46, 793, 207, 632, 179, 660, 1

7、45, 694, 130, 709, 223, 616136167228, 611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678, 201, 638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10, 829, 9, 8301682037, 832, 8, 831, 16, 823, 47, 792, 64, 775, 57, 782, 104, 735, 101, 738, 108, 731, 208, 631, 184, 655, 197, 642

8、, 191, 648, 121, 718, 141, 698, 149, 690, 216, 623, 218, 621204263152, 687, 144, 695, 134, 705, 138, 701, 199, 640, 162, 677, 176, 663, 119, 720, 158, 681, 164, 675, 174, 665, 171, 668, 170, 669, 87, 752, 169, 670, 88, 751, 107, 732, 81, 758, 82, 757, 100, 739, 98, 741, 71, 768, 59, 780, 65, 774, 50

9、, 789, 49, 790, 26, 813, 17, 822, 13, 826, 6, 8332643275, 834, 33, 806, 51, 788, 75, 764, 99, 740, 96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163, 676, 185, 654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195, 644, 192, 647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123

10、, 716, 139, 700, 212, 627, 153, 686, 213, 626, 215, 624, 150, 689328383225, 614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715, 193, 646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672, 79, 760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785, 36, 803, 32, 807,

11、 25, 814, 18, 821, 11, 828, 4, 8353844553, 836, 19, 820, 22, 817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63, 776, 67, 772, 72767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730, 165, 674, 111, 728, 209, 630, 204, 635, 117, 722, 188, 651, 159, 680, 198, 641, 113, 726, 183, 656, 180, 659, 177, 66

12、2, 196, 643, 155, 684, 214, 625, 126, 713, 131, 708, 219, 620, 222, 617, 226, 613456513230, 609, 232, 607, 262, 577, 252, 587, 418, 421, 416, 423, 413, 426, 411, 428, 376, 463, 395, 444, 283, 556, 285, 554, 379, 460, 390, 449, 363, 476, 384, 455, 388, 451, 386, 453, 361, 478, 387, 452, 360, 479, 310

13、, 529, 354, 485, 328, 511, 315, 524, 337, 502, 349, 490, 335, 504, 324, 515514561323, 516, 320, 519, 334, 505, 359, 480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458, 399, 440, 380, 459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432, 281, 558, 414, 425, 247, 592, 277, 562, 271, 568, 272, 567,

14、 264, 575, 259, 580562629237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561, 250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469, 365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527, 313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489, 326,

15、513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517630659330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538, 366, 473, 401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570, 238, 601, 234, 605660707257, 582, 273, 566, 255, 584, 254, 585, 245, 594, 251, 588, 412, 427, 372, 46

16、7, 282, 557, 403, 436, 396, 443, 392, 447, 391, 448, 382, 457, 389, 450, 294, 545, 297, 542, 311, 528, 344, 495, 345, 494, 318, 521, 331, 508, 325, 514, 321, 518708729346, 493, 339, 500, 351, 488, 306, 533, 289, 550, 400, 439, 378, 461, 374, 465, 415, 424, 270, 569, 241, 598730751231, 608, 260, 579,

17、 268, 571, 276, 563, 409, 430, 398, 441, 290, 549, 304, 535, 308, 531, 358, 481, 316, 523752765293, 546, 288, 551, 284, 555, 368, 471, 253, 586, 256, 583, 263, 576766777242, 597, 274, 565, 402, 437, 383, 456, 357, 482, 329, 510778789317, 522, 307, 532, 286, 553, 287, 552, 266, 573, 261, 578790795236

18、, 603, 303, 536, 356, 483796803355, 484, 405, 434, 404, 435, 406, 433804809235, 604, 267, 572, 302, 537810815309, 530, 265, 574, 233, 606816819367, 472, 296, 543820837336, 503, 305, 534, 373, 466, 280, 559, 279, 560, 419, 420, 240, 599, 258, 581, 229, 610Preamble逻辑根序列号索引Preamble物理根序列号索引 (按逻辑根序列号升序排列

19、) Format4 (36.211 table5.7.2-5)0 191138213731364135513461337132813191301012920 391112812127131261412515124161231712218121191202011940 592111822117231162411525114261132711228111291103010960 79311083210733106341053510436103371023810139100409980 994198429743964495459446934792489149905089100 11951885287

20、53865485558456835782588159806079120 137617862776376647565746673677268716970-PRACH的根序列产生公式：是根ZC序列的长度,u为第u个根序列编号，然后通过循环移位这两种ZC序列,长度分别为839bit和139bit.这两种序列协议把它称为根序列RootSequence,以839bit的序列为例,这种序列的个数=长度-1=838个.这838个序列中任意两个根序列都是相互正交和无干扰的.拿其中任何一个序列,由于序列上有839个点,选择任意一个点作为起点逆时针转一圈,都能得到一条序列,这样一条序列就叫一个Preamble,那

21、总共838个根序列,每个根序列上有839个点,故每条根序列能产生839条Preamble,则总共的Preamble总数=838*839=703082条Preamble.任意两条Preamble都是相互正交和无干扰的. 参数:也是与小区覆盖半径决定的,比如小区覆盖半径为14公里时,Ncs索引取值一般可以是11(12.52KM)或10(10.09KM),它是Preamble的Cyclic shift，目前只支持非限制集，限制集只适用于高速场景。若取值为11，则表示在此圆上每隔93个点取一个,每两个循环移位间隔为93,由于长度为839，因此这条根序列能产生=int(839/9)=9，即一条根序列可产

22、生9个preamble，因此需要ubound(64/9)=8个根序列，因此规划时每小区的root-sequence差8，=11。的大小决定小区半径，例取11，则小区半径=93*preamble时长/preamble长度/2=800us*间隔93*C光速/839/2=13.3km，其中800us*间隔93就是指间隔的时延。 NCS 配置(preamble format4见36.211 table5.7.2-3)NCS值021426384105126151.1.3 上行RACH信道资源preamble种类个数及划分细则 每个小区都有64(编号为063)个Preamble码,协议把它划分为2组,用于

23、UE与网络侧的随机接入同步过程.一组是网络侧eNB指定分配给UE的preamble码,这种称为专用或非竞争的,这个码其它用户不能使用;另一组是UE自已随机选的,大家都可以用,这种称为竞争性的随机接入码.有参数指定随机接入码的个数numberOfRA-Preambles,此参数在SIB2中下发.如果此参数为48个(编号为047),则剩下的就是专用的Preamble码(4863).同时协议又将竞争的分为GroupA和GroupB两组.具体如下图: 如果是竞争性的Preamble,那到底选用GroupA还是GroupB呢?在此需要提醒一下,假如eNB在随机接入用户同时很多的时候,eNB对GroupB

24、比GroupA的优先级要高点.因此eNB选择GroupB时,需满足两个条件:1).UE的信号要好,这样才能保证优先处理时的可靠性更高(链路损耗要小些)pathloss<pathlossThreshold pathlossThreshold=Pmax- preambleInitialReceivedTargetPower deltaPreMsg3messagePowerOffsetGroupB 2).手机中有较大的上行数据块要发送(preamble中需要承载的消息量+MAC header大小)> messageSizeGroupA,有些厂家将此参数写为(raSmallVolUl)1.

25、1.4 上行RACH信道资源preamble频域位置 前面讲过,PRACH资源占频域的上行6个PRB,fomat03格式的Preamble的长度为839bit, 每个子载波的带宽为1.25KHZ, 则占用频域带宽为=7.5KHZ*839=1.048M,占用连续6个PRB(1.08M)的带宽;长度为139bit的Preamble的子载波的带宽为7.5JHZ,则同样占用7.5KHZ*139=1.0425M(连续6个PRB)的带宽. 在20MHZ的带宽下,上行总共有100个PRB,那PRACH到底在哪几个PRB呢.这与PRACHConfigIndex和上下行子帧配置有关.参数PRACHConfig是

26、指PRACH的format格式,其中包含了一个无线帧内PRACH信道的个数(称为PRACH密度Density,1代表每无线帧出现一次,0.5代表第2个无线帧出现一次,其它按此类推).PRACHconfigurationIndexPreambleFormatDensity(Per10 msDRA)VersionVRAPRACHconfigurationIndexPreambleFormatDensity(Per10 msDRA)VersionVRA000.503220.52100.5133210200.52342113（目前配置）01(preamble时长1ms)0352204011362305

27、0123724060203825070213926080224030.5090304130.51100314230.5211032433101204044311130414532014042463301505047340160514840.50170524940.51180605040.5219061514102010.50524112110.51534202210.52544302311055440241115645025120574602613058N/AN/AN/A2714059N/AN/AN/A2815060N/AN/AN/A2916061N/AN/AN/A3020.5062N/AN/

28、AN/A3120.5163N/AN/AN/APRACH configuration Index (See Table 5.7.1-3)TDD PRACH的时间的频域位置UL/DL configuration (See Table 4.2-2)01234560(0,1,0,2)(0,1,0,1)(0,1,0,0)(0,1,0,2)(0,1,0,1)(0,1,0,0)(0,1,0,2)1(0,2,0,2)(0,2,0,1)(0,2,0,0)(0,2,0,2)(0,2,0,1)(0,2,0,0)(0,2,0,2)2(0,1,1,2)(0,1,1,1)(0,1,1,0)(0,1,0,1)(0,1,0,

29、0)N/A(0,1,1,1)3(0,0,0,2)(0,0,0,1)(0,0,0,0)(0,0,0,2)(0,0,0,1)(0,0,0,0)(0,0,0,2)4(0,0,1,2)(0,0,1,1)(0,0,1,0)(0,0,0,1)(0,0,0,0)N/A(0,0,1,1)5(0,0,0,1)(0,0,0,0)N/A(0,0,0,0)N/AN/A(0,0,0,1)6(0,0,0,2)(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,0,0)(0,0,0,0)(0,0,0,2)(0,0,1,2)(0,0,1,1)(0,0,1,0)(0,0,0,2)(0,0,0,1)(1,0,0,0)

30、(0,0,1,1)7(0,0,0,1)(0,0,0,0)N/A(0,0,0,0)N/AN/A(0,0,0,1)(0,0,1,1)(0,0,1,0)(0,0,0,2)(0,0,1,0)8(0,0,0,0)N/AN/A(0,0,0,0)N/AN/A(0,0,0,0)(0,0,1,0)(0,0,0,1)(0,0,1,1)9(0,0,0,1)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,1)(0,0,0,2)(0,0,0,1)(0,0,1,0)(0,0,0,1)(0,0,0,1)(1,0,0,0)(0,0,0,2)(0,0,1,2)(0,0,1

31、,1)(1,0,0,0)(0,0,0,2)(1,0,0,1)(2,0,0,0)(0,0,1,1)10 (0,0,0,0)(0,0,0,1)(0,0,0,0)N/A(0,0,0,0)N/A (0,0,0,0)(0,0,1,0) (0,0,1,0)(0,0,1,0)(0,0,0,1)(0,0,0,2)(0,0,1,1)(0,0,1,1)(1,0,1,0)(1,0,0,0)(0,0,1,0)11N/A(0,0,0,0)N/AN/AN/AN/A (0,0,0,1)(0,0,0,1)(0,0,1,0)(0,0,1,0)(0,0,1,1)12(0,0,0,1)(0,0,0,0)(0,0,0,0)(0,0,

32、0,0)(0,0,0,0)(0,0,0,0)(0,0,0,1)(0,0,0,2)(0,0,0,1)(0,0,1,0)(0,0,0,1)(0,0,0,1)(1,0,0,0)(0,0,0,2)(0,0,1,1)(0,0,1,0)(1,0,0,0)(0,0,0,2)(1,0,0,0)(2,0,0,0)(0,0,1,0)(0,0,1,2)(0,0,1,1)(1,0,1,0)(1,0,0,2)(1,0,0,1)(3,0,0,0)(0,0,1,1)13(0,0,0,0)N/AN/A(0,0,0,0)N/AN/A(0,0,0,0)(0,0,0,2)(0,0,0,1)(0,0,0,1)(0,0,1,0)(0,

33、0,0,2)(0,0,0,2)(0,0,1,2)(1,0,0,1)(0,0,1,1)14(0,0,0,0)N/AN/A(0,0,0,0)N/AN/A(0,0,0,0)(0,0,0,1)(0,0,0,1)(0,0,0,2)(0,0,1,0)(0,0,0,2)(0,0,1,0)(0,0,1,1)(1,0,0,0)(0,0,1,1)15(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,1)(0,0,0,1)(0,0,1,0)(0,0,0,1)(0,0,0,1)(1,0,0,0)(0,0,0,1)(0,0,0,2

34、)(0,0,1,0)(1,0,0,0)(0,0,0,2)(1,0,0,0)(2,0,0,0)(0,0,0,2)(0,0,1,1)(0,0,1,1)(1,0,1,0)(1,0,0,1)(1,0,0,1)(3,0,0,0)(0,0,1,0)(0,0,1,2)(1,0,0,1)(2,0,0,0)(1,0,0,2)(2,0,0,1)(4,0,0,0)(0,0,1,1)16(0,0,0,1)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,0)N/AN/A(0,0,0,2)(0,0,0,1)(0,0,1,0)(0,0,0,1)(0,0,0,1)(0,0,1,0)(0,0,1,0)(1,

35、0,0,0)(0,0,0,2)(1,0,0,0)(0,0,1,1)(0,0,1,1)(1,0,1,0)(1,0,0,0)(1,0,0,1)(0,0,1,2)(1,0,1,1)(2,0,1,0)(1,0,0,2)(2,0,0,0)17(0,0,0,0)(0,0,0,0)N/A(0,0,0,0)N/AN/AN/A(0,0,0,1)(0,0,0,1)(0,0,0,1)(0,0,0,2)(0,0,1,0)(0,0,0,2)(0,0,1,0)(0,0,1,1) (1,0,0,0)(0,0,1,2)(1,0,0,0)(1,0,0,1)18(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,

36、0)(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,0,1)(0,0,0,1)(0,0,1,0)(0,0,0,1)(0,0,0,1)(1,0,0,0)(0,0,0,1)(0,0,0,2)(0,0,1,0)(1,0,0,0)(0,0,0,2)(1,0,0,0)(2,0,0,0)(0,0,0,2)(0,0,1,0)(0,0,1,1)(1,0,1,0)(1,0,0,0)(1,0,0,1)(3,0,0,0)(0,0,1,0)(0,0,1,1)(1,0,0,1)(2,0,0,0)(1,0,0,1)(2,0,0,0)(4,0,0,0)(0,0,1,1)(0,0,1,2)(1,0,1,1)(

37、2,0,1,0)(1,0,0,2)(2,0,0,1)(5,0,0,0)(1,0,0,2)19N/A(0,0,0,0)N/AN/AN/AN/A(0,0,0,0)(0,0,0,1)(0,0,0,1)(0,0,1,0)(0,0,0,2)(0,0,1,1)(0,0,1,0)(1,0,0,0)(0,0,1,1)(1,0,1,0)(1,0,1,1)20 / 30(0,1,0,1)(0,1,0,0)N/A(0,1,0,1)(0,1,0,0)N/A(0,1,0,1)21 / 31(0,2,0,1)(0,2,0,0)N/A(0,2,0,1)(0,2,0,0)N/A(0,2,0,1)22 / 32(0,1,1,1

38、)(0,1,1,0)N/AN/AN/AN/A(0,1,1,0)23 / 33(0,0,0,1)(0,0,0,0)N/A(0,0,0,1)(0,0,0,0)N/A(0,0,0,1)24 / 34(0,0,1,1)(0,0,1,0)N/AN/AN/AN/A(0,0,1,0)25 / 35(0,0,0,1)(0,0,0,0)N/A(0,0,0,1)(0,0,0,0)N/A(0,0,0,1)(0,0,1,1)(0,0,1,0)(1,0,0,1)(1,0,0,0)(0,0,1,0)26 / 36(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,1,1)(

39、0,0,1,0)N/A(1,0,0,1)(1,0,0,0)N/A(0,0,1,0)(1,0,0,1)(1,0,0,0)(2,0,0,1)(2,0,0,0)(1,0,0,1)27 / 37(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,1,1)(0,0,1,0)N/A(1,0,0,1)(1,0,0,0)N/A(0,0,1,0)(1,0,0,1)(1,0,0,0)(2,0,0,1)(2,0,0,0)(1,0,0,1)(1,0,1,1)(1,0,1,0)(3,0,0,1)(3,0,0,0)(1,0,1,0)28 / 38(0,0,0,1)(0,0,

40、0,0)(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,1,1)(0,0,1,0)(1,0,0,1)(1,0,0,0)(0,0,1,0)(1,0,0,1)(1,0,0,0)N/A(2,0,0,1)(2,0,0,0)N/A(1,0,0,1)(1,0,1,1)(1,0,1,0)(3,0,0,1)(3,0,0,0)(1,0,1,0)(2,0,0,1)(2,0,0,0)(4,0,0,1)(4,0,0,0)(2,0,0,1)29 /39(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,0,0)(0,0,0,1)(0,0,1,1)(0,0,1,0)(1,0,0,1)(1,0,

41、0,0)(0,0,1,0)(1,0,0,1)(1,0,0,0)N/A(2,0,0,1)(2,0,0,0)N/A(1,0,0,1)(1,0,1,1)(1,0,1,0)(3,0,0,1)(3,0,0,0)(1,0,1,0)(2,0,0,1)(2,0,0,0)(4,0,0,1)(4,0,0,0)(2,0,0,1)(2,0,1,1)(2,0,1,0)(5,0,0,1)(5,0,0,0)(2,0,1,0)40(0,1,0,0)N/AN/A(0,1,0,0)N/AN/A(0,1,0,0)41(0,2,0,0)N/AN/A(0,2,0,0)N/AN/A(0,2,0,0)42(0,1,1,0)N/AN/AN/

42、AN/AN/AN/A43(0,0,0,0)N/AN/A(0,0,0,0)N/AN/A(0,0,0,0)44(0,0,1,0)N/AN/AN/AN/AN/AN/A45(0,0,0,0)N/AN/A(0,0,0,0)N/AN/A(0,0,0,0)(0,0,1,0)(1,0,0,0)(1,0,0,0)46(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,1,0)N/AN/A(1,0,0,0)N/AN/A(1,0,0,0)(1,0,0,0)(2,0,0,0)(2,0,0,0)47(0,0,0,0)(0,0,0,0)(0,0,0,0)(0,0,1,0)N/AN/A(1,0,0,0)N/AN

43、/A(1,0,0,0)(1,0,0,0)(2,0,0,0)(2,0,0,0)(1,0,1,0)(3,0,0,0)(3,0,0,0)48(0,1,0,*)(0,1,0,*)(0,1,0,*)(0,1,0,*)(0,1,0,*)(0,1,0,*)(0,1,0,*)49(0,2,0,*)(0,2,0,*)(0,2,0,*)(0,2,0,*)(0,2,0,*)(0,2,0,*)(0,2,0,*)50(0,1,1,*)(0,1,1,*)(0,1,1,*)N/AN/AN/A(0,1,1,*)51(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0

44、,0,0,*)52(0,0,1,*)(0,0,1,*)(0,0,1,*)N/AN/AN/A(0,0,1,*)53(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,1,*)(0,0,1,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(0,0,1,*)54(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,1,*)(0,0,1,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*

45、)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(2,0,0,*)(2,0,0,*)(2,0,0,*)(1,0,0,*)55(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,1,*)(0,0,1,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(2,0,0,*)(2,0,0,*)(2,0,0,*)(1,0,0,*)(1,0,1,*)(1,0,1,*)(1,0,1,*)(3,0,0,*)

46、(3,0,0,*)(3,0,0,*)(1,0,1,*)56(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,1,*)(0,0,1,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(2,0,0,*)(2,0,0,*)(2,0,0,*)(1,0,0,*)(1,0,1,*)(1,0,1,*)(1,0,1,*)(3,0,0,*)(3,0,0,*)(3,0,0,*)(1,0,1,*)(2,0,0,*)(2,0,0,*)(

47、2,0,0,*)(4,0,0,*)(4,0,0,*)(4,0,0,*)(2,0,0,*)57(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,0,*)(0,0,1,*)(0,0,1,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(0,0,1,*)(1,0,0,*)(1,0,0,*)(1,0,0,*)(2,0,0,*)(2,0,0,*)(2,0,0,*)(1,0,0,*)(1,0,1,*)(1,0,1,*)(1,0,1,*)(3,0,0,*)(3,0,0,*)(3,0,0,*)(1,0,1,*)(2

48、,0,0,*)(2,0,0,*)(2,0,0,*)(4,0,0,*)(4,0,0,*)(4,0,0,*)(2,0,0,*)(2,0,1,*)(2,0,1,*)(2,0,1,*)(5,0,0,*)(5,0,0,*)(5,0,0,*)(2,0,1,*)58N/AN/AN/AN/AN/AN/AN/A59N/AN/AN/AN/AN/AN/AN/A60N/AN/AN/AN/AN/AN/AN/A61N/AN/AN/AN/AN/AN/AN/A62N/AN/AN/AN/AN/AN/AN/A63N/AN/AN/AN/AN/AN/AN/A以PRACHconfigIndex=3和上下行子帧配置=2(1:3)为例,其

49、交集为(0,0,0,0).组合中(0,0,0,0),第一个0就是指PRACH的频域的位置的值,在此组合中为0, .其频域真正位置为.由于=0,因此=参数就是指PRACH信道离带宽两端边界的PRB编号0或100的偏离位置,如果PRACH在带宽底端,且要占用6个PRB,则=5(PRAB编号05,共6个PRB是PRACH信;) ;如果PRACH在带宽顶端,且要占用6个PRB,则=94(PRAB编号9499,共6个PRB是PRACH信道).因为考虑到上行SC-FDMA的特性,上行PUSCH必须要参够连续且可以过到最大的峰值速率,因此协议规定PRACH只能位于带宽的两端.1.1.5 上行RACH信道资源preamble时域位置前面讲PRACH频域位置时讲过,PRACH的频域位置与PRACHconigIndex/上下行子帧配置/参数这3个因素决定. 同样以PRACHConfigIndex=3且上行下子帧配置为2时,还是组合(0,0,0,0),那这个组合不仅决定了PRACH的PRACH的频域位置,也同样决定PRACH的时域位置.具体是此组合的后面3个值决定了PRACH的时域位置.对应组合(0,0,0,0)中第2个0是