TW200947988A - Method of transmitting reference signal and transmitter using the same - Google Patents

Abstract

A method and apparatus of transmitting a reference signal in a wireless communication system is provided. A reference signal sequence is generated by using a pseudo-random sequence. A portion or entirety of the reference signal sequence is mapped to at least one resource block and is transmitted. The pseudo-random sequence is generated by a gold sequence generator which is initialized with initial values obtained by using cell identifier. The reference signal provides low PAPR and high cross correlation characteristic.

Description

200947988 VI. INSTRUCTIONS: • Technical Field to Which the Invention pertains The present invention relates to wireless communications; and more particularly to the generation and application of a reference signal sequence in a wireless communication system. [Prior Art] Wireless communication systems are widely used throughout the world to provide various types of communication services such as voice or material. In general, a wireless communication system is a multiplex access system that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of multiplex access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, and time division multiple access (Time division multiple) Access, TDMA) system, Orthogonal frequency division multiple access (OFDMA) system, Single carrier frequency division multiple access (SC-FDMA) system, and the like. In wireless communication systems, sequences are often used for a variety of purposes, such as reference signals, scrambling codes, and the like. Sequences used in wireless communication systems typically meet the following characteristics. 4 200947988 (1) Good correlation characteristics' to provide high detection performance. (7) Low peak average power ratio (Peak_to_average p〇wer PAPR)' in order to improve the efficiency of the power amplifier. (3) Generate a large number of sequences to transmit a large amount of information or to assist in cell service area planning. Although a constant amplitude and zero auto correlati 参 CA CAZAC sequence with good PAPR characteristics has been proposed, the number of available sequences is limited. Therefore, many wireless communication systems use sequences that are generated in a random manner. The advantage of a class-like random sequence is that a large number of sequences are available, but the problem is that there is a high PAPR in a particular pattern. A variety of binary or non-binary random sequences have been used in wireless communication systems. These random sequences can be easily generated using the M-stage linear feedback shift register (LFSR) and have exceptional random characteristics. A m-sequence will be used as a scrambling code in a wideband CDMA (Wideband CDMA, WCDMA) system because the structure of the m-sequence is simpler than the non-binary-like random sequence. The gold sequence utilizes a class-like random sequence generated by two different binary m sequences. The gold sequence can be easily implemented using two m-level LFSRs. The advantage of the gold sequence is that by changing the initial state of each m-level LFSR, different class-like random sequences can be generated according to one cycle. Accordingly, there is a need for a method that produces a sequence with improved pApR and associated properties 200947988. SUMMARY OF THE INVENTION The present invention provides a transmission method and apparatus in a wireless communication system in a helmet. In addition, reference signals are also provided and sent. The receiver is configured to receive the transmitted code. The present invention also provides a method and apparatus for transmitting a serial number in a wireless communication system. In addition, a sequenced transmit sequencer is provided for receiving a method of transmitting a reference signal in a wireless communication system. The method includes generating a reference signal sequence, mapping: a portion or all of the test signal sequence to at least -RB; and transmitting - the reference signal in the at least - RB. The reference signal sequence is defined by: %, (m) = -^(1 - 2 · c{2m))+j^x _ 2. c(2/w + ^ m = 〇lj 2iV« -1 Where ns is the number of time slots in a radio frame, / is the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time slot, and ^^ is a Resource Block (RB) The maximum number of classes. The class-like random sequence c(1) is generated by a prime sequence derived from the initial value obtained by (2 + 1), which is the cell service area identification code. The class random sequence C(i) can be Defined below: c(i) = (x(i + Nc) + y(i + Nc)) mod 2 x(i + 31) = (x(i + 3) + x(i)) mod 2 y( i + 31) = (y(i + 3) + y(i + 2) + y(i + 1) + y(i)) mod 2 where 'x(i) and y(i) are m sequences, and Nc is a constant. The m-sequence x(i) can be initialized by χ(0)=1 ' x(i)=〇, iq, 2 '..., 30, and the m-sequence (y) can be initialized with these initial values. It may be a value ranging from 1500 to 1800. These initial values may change as the number of 〇FDM symbols changes. These initial values can be obtained using ί(2Α^«+1). Size of the initial values may be 31 bits.

An RB may include 12 subcarriers in the frequency domain. The two modulated symbols in the reference signal sequence can be mapped to two secondary carriers in one RB. The reference signal may be a common reference signal of a cell service area or a user equipment (UE) specific reference signal. In another aspect, the transmitter includes: a reference signal generator for generating a reference signal; and a transmitting circuit system for transmitting the reference signal. The reference signal generator generates the reference signal by generating a sequence of reference 彳s numbers defined below: 200947988 ^(^) = ^(1-2.^))+7-1(1-2.^ + 1)), W = 0,1,...,2^DL -1 where 'heart is the number of slots in a radio frame, / is the number of OFDM symbols in a slot' and is a resource block ( The maximum number of RBs. The class random sequence c(i) is generated by a gold sequence generator initialized with an initial value obtained by (2i^U+1), which is a cell service area identification code. The reference signal generator maps a portion or all of the reference signal sequence to at least one RB. In another aspect, a receiver includes: a receiving circuit system for receiving a reference signal and a receiving signal; a channel evaluator for evaluating a channel by using the reference k number; and - a data processor Used to utilize the channel to process the received signal. The reference signal is generated based on a reference signal sequence defined below: ❹ (w) = -^(1 - 2 c(2m))+j~(\ - 2 · C(2m+1)), m = 0, lv.., 2iV^DL _ ι where ns is the number of slots in a radio frame w is the number of symbols in the slot, and ^^ is the maximum number of resource blocks (rb) . The class-like random sequence c(1) is a gold sequence generator initialized by an initial value obtained by (2 <+1) to generate 'where'-cell service area identification code β power ratio (PAPR) and the sequence proposed by the present invention Provides a low peak average of 8 200947988 high correlation characteristics. Therefore, the transmission power can be efficiently provided in the transmitter, and the signal detection performance can be improved in the receiver. The sequence proposed by the present invention can be used for reference signals requiring high reliability and can be used for other scrambling codes. [Embodiment] The technology described below can be used in various radio access technologies, including, for example, code division multiplexing access (CDMA), frequency division multiplexing access (FDMA), time division multiplexing access (TDMA), and positive Interleaved Frequency Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and the like. CDMA can be implemented using radio technology, such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technology, such as Global System for Mobile communication (GSM) / General Packet Radio. Service (GPRS) / GSM Enhanced Data Rates for GSM (Enhanced Data Rates for GSM) Evolution, EDGE). OFDMA can be implemented using radio technology, such as Institute of electrical and electronics engineer (IEEE) 802.11 (Wi-Fi) 'IEEE 802.1 6 (WiMAX) 'IEEE 802-20, deductive UTRA (Evolved UTRA, E-UTRA) and so on. UTRA is part of the Universal Mobile Telecommunication System (UMTS). The third generation of actions 200947988 3rd generation partnerjship project (3GPP) Long term evolution (LTE) is part of the evolutionary UMTS (Evolved-UMTS, E-UMTS) using E-UTRA. 3GPP LTE uses OFDMA in the downlink and SC-FDMA in the uplink. LTE-advance (LTE-advance, LTE-A) is an evolution of 3GPP LTE. For the sake of clarity, the following description will focus on 3GPP LTE/LTE-A. However, the technical features of the present invention are not limited thereto. Figure 1 shows a wireless communication system. Referring to FIG. 1, the wireless communication system 10 includes at least one base station (BS) 11. BS 11 provides communication services for specific geographic areas (known as cell service areas) 15a, 15b and 15c. The cell service area can be divided into a plurality of areas (referred to as segments). The User Equipment (UE) 12 may be fixed or movable, and may be referred to by another term, such as a Mobile Station (MS). User terminal (UT), subscriber station (SS), wireless device, personal digital assistant (PDA), wireless data device, handheld device, and the like. The BS 11 is usually a fixed station that communicates with the UE 12 and can be referred to by another term, such as an Evolved node-B (eNB), a Base Transceiver System (BTS), an access point. Wait. Hereinafter, the downlink key is the communication key from the BS to the UE, and the up key 200947988 is the communication link from the up to the end. In the downlink, the transmission may be part of the BS, and the receiver may be part of the fairy. In the uplink, the transmitter may be part of the UE that is part of the BS. The receiver may be the structure of the radio frame in 3Gpp LTE as shown in Fig. 2. Referring to Figure 2, the radio frame contains 10 sub-frames. A sub-frame contains two time wheels. The time used to transmit a sub-frame with hot ‘, pen T Jr- ❹ 会 is defined as the Transmassion time interval (ΤΤΙ). For example, the length of a sub-frame may be 1 millisecond (mS), and the length of a - time slot may be 0.5 ms. A time slot includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain. Since 3GPP LTE uses 〇FDMA in the downlink, the OFDM symbol is used to represent one symbol period. According to a system, an OFDM symbol can also be referred to as an SC_FDMA # number or symbol period. The resource block_system-resource allocation unit' includes a plurality of consecutive subcarriers in the time slot. The structure of the radio frame shown in the figure is for exemplary purposes only. Therefore, the number of subframes contained in the radio frame or the number of slots included in the subframe or the number of 〇FDM symbols contained in the slot can be corrected in various ways. Figure 3 shows an example of a resource grid for a downlink time slot. Referring to Figure 3, the downlink time slot contains a plurality of 11 200947988 OFDM symbols in a time domain. In the example described herein, the downlink time slot contains 7 OFDM symbols, and a resource block (RB) contains 12 secondary carriers in a frequency domain. However, the invention is not limited thereto. Each component in the resource grid is called a resource element. One RB contains 12x7 resource elements. The number of RBs included in the downlink slot NDb will be based on the downlink transmission bandwidth. The exemplary structure of the downlink subframe is shown in FIG. ❹ Referring to Figure 4, the sub-frame contains two time slots. The maximum number of three OFDM symbols in the front part of the slot in the subframe is corresponding to the control area to be allocated with the control channel. The remaining OFDM symbols correspond to the data area to be allocated in conjunction with a physical downlink shared channel (PDSCH). Examples of downlink control channels used in 3GPP LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), and a physical hybrid ARQ indicator. (Physical hybrid ARQ indicator channel, PHICH), etc. The PCFICH is transmitted at the first OFDM symbol of a subframe and carries information relating to the number of OFDM symbols used to transmit the control channel within the subframe. The control information transmitted via the PDCCH is referred to as Downlink Control Information (DCI). The DCI contains uplink or downlink scheduling information or an uplink transmit power control command containing any 12 200947988 intended UE group. The reference signal will now be explained. When the data is transmitted in the wireless communication system, the transmitted data can be distorted on the radio channel. In order for the receiver to restore the distorted data to the original data, the channel status must be known in order to compensate for the distortion of the received signal based on the channel status. In order to know the channel status, a signal known in advance by both the transmitter and the receiver is used. This signal is called the reference apostrophe or the preamble. Since the reference signal is an important signal for the channel state, the transmitter transmits the reference signal at a transmission power greater than that of the other signals. Furthermore, to distinguish between reference signals transmitted between multiple cell service areas in a multi-cell service area environment, the reference signal must have good peak-to-average power ratio (PAPR) and correlation characteristics. The reference signal can be divided into a cell service area common reference signal and a UE-specific reference signal. The cell service area common reference signal is a reference signal used by all UEs within a cell service area. The UE-specific reference signal is a reference signal used by a UE in the cell service area or used by a UE group. The figure shown in Fig. 5 is an exemplary structure in which the downlink links refer to the 彳s number when the BS uses one antenna. Figure 6 shows an exemplary structure of the downlink common reference signal when bS uses two antennas. Figure 7 shows an exemplary structure of the joint reference signal when the BS uses four antennas. This can be found in section 6.10.1 of 3GPP TS 36.211 V8.0.0 (2〇〇7·〇9) "Evolved Universal Terrestrial Radio Access 13 200947988 (E-UTRA); Physical channels and modulation (8th Edition)" . Rp represents the reference signal of the pth antenna (here pe{0, 1, 2, 3}). 110 to 113 do not overlap each other. In the 〇?〇]^ symbol, each Rp is positioned as an interval of 6 subcarriers. Therefore, if an RB contains 12 subcarriers, an RB requires a sequence having a length of 2 sequences (or two modulation symbols). In a sub-frame, the number of R0 is equal to the number of R1, and the number of R2 is equal to the number of R3 φ. Within this subframe, the number of R2 and R3 is less than the number of R0 and R1. Rp is not used to transmit with the antenna except for the Pth antenna. This is to prevent interference between the antennas. The generation of a sequence of reference signals will now be described. The system to be discussed utilizes a reference signal generated by a gold sequence generator. A golden sequence can be implemented using two Class 3 linear feedback shift registers (LFSRs). Suppose that φ "0000000000000000000000000000001" is used to initialize the two

The first LFSR in the LFSR is "χ(30)χ(29)χ(28)·_·χ(2)χ(1)χ(0)”. In addition, the initial value of the second LFSR depends on the Cell Service Area Identifier (ID), the sub-frame number, and the OFDM symbol number. The cell service area ID indicates an ID unique to a cell service area. The sub-frame number indicates the indicator of a sub-frame in a radio frame. The OFDM symbol number indicates an indicator of an OFDM symbol within a subframe (or time slot). 14 200947988 Figure 8 is an example of a gold sequence generator. The first melon sequence x(i) uses a sequence to generate a polynomial D3i+D3+1, and the second m-sequence y(i) uses a sequence to generate a polynomial D31+D3+D2+D+1. These two m sequences are used to generate a class of random sequences c(i). This kind of random sequence c(1) is generated by the generator polynomial of Equation 1 shown below: [Formula 1] © c(〇= (x(z') + mod 2 x(i + 31) = (x(i + 3 ) + x(/))mod 2 y(i + 31) = (;;(/ + 3) + y(i + 2) + y{i + 1) + y(i)) m〇d 2 where ' I- 0,1,...,Mmax -1 ' and Mmax is the length of the binary-like random sequence generated by the gold sequence. In a class-like random sequence with a length Mmax, only a part of the sequence may be If the length of the sequence ❹ column using only a part of the class-like random sequence having the length Mmax is used, the MS Mmax °M may be changed according to the number of rbs used for data transmission. The number of available RBs is according to the 3GPP LTE system. The available bandwidth varies, so the value Μ can also be changed according to the number of assigned rbs. If it is the first LFSR 'the initial values will be fixed as above for "0000000000000000000000000000001". The initial value of the second LFSR It depends on the cell service area ID, the subframe number and the OFDM symbol 15 200947988 \ number. The setting of the initial value of the second LFSR is shown in Figure 9. Among the 3 1 bits of the initial value, the 17-bit from the Least significant bit (LSB) will be 9-bit cell service area ID, 4-bit subframe number, and 4-bit OFDM. The symbol number is initialized. 3GPP LTE supports 5 04 unique cell service area IDs. Therefore, the cell service area ID ranges from 0 to 503. A radio frame contains 10 subframes, so the subframe number ranges from 0. Up to 9. A sub-frame may contain up to 14 OFDM symbols, so the OFDM symbol number ranges from 0 to 13. The remaining 14 bits from the Most Signi Hcant bit (MSB) will be "0" Initialization. The initial value of the second LFSR can be expressed in the following table: [Table 1] x(30) x(29) x(28) x(27) x(26)............ ...x(3)x(2)x(l] X(9) Set to zero OFDM symbol number sub-frame number cell service area ID 14 bits 4 bits 4 bits 9 bits above Table 1, cell service area The ID, the OFDM symbol number, and the range of the subframe number and/or the number of bits are for demonstration purposes only and are not limited thereto. For example, the subframe number can be represented by a slot number. Because of a wireless 16 200947 The 988 telecommunications frame contains 20 time slots'. Therefore, the time slot number ranges from 〇 to ι9β after determining the initial value of the first LFSR and the initial value of the second LFSR, 'part of the random sequence of the class generated by the gold sequence generator. The sequence generated by or as a reference signal will be modulated into a modulation symbol ' via quadrature phase shift keying (QPSK) modulation and then mapped to each resource element. In this case, only one e portion of the gold sequence of a particular size generated in advance can be used. For example, as shown in Fig. 5, the 'reference signal' can be mapped to two subcarriers having 6 subcarrier spacings among the 12 subcarriers constituting one RB. However, when a random sequence is generated as described above, the ratio of "〇" to "1" may be different from that in the binary sequence that has been generated. Therefore, the number of "〇" may be greater than "1". The number of quantities or Γ" may be greater than the number of "0". In this case, even if the QpSK modulation is implemented, the direct current (DC) component will still exist due to the deviating random sequence. Therefore, the PAPR characteristics may be degraded by the inverse fast Fourier transform (IFFT) process. Taking a representative example as an example, if the cell service area ID, the subframe number, and the OFDM symbol number are all "〇", the 31 bits of the second LFSR& initial value are all set to "〇". Figure 10 is a diagram for comparing the magnitude of a reference signal and any material when the initial values of the second LFSR are all set to "〇". When the initial value of the gold sequence generator is 31 bits all "

When 0 J is initialized, a reference signal with a size much larger than any other data is generated at some time, which is a metaphor for PAPR characteristics. Figure 11 shows the problem caused by the initial value of the gold sequence in a multi-cell service area environment. In a multi-cell service area environment, each cell service area has a unique cell service area ID. However, because only 9 of the 31 bits of the initial values are different, if the remaining 22 bits are the same, a pair of random random numbers for each cell service area can be generated. sequence. Specifically, up to 30 bits of the initial value of 31 cells may overlap if the cell service area IDs in each of the cell service areas are consecutive. Therefore, when the generated random sequence of the class is used as the reference signal, the correlation characteristic may be deteriorated. The sequence generated by the generation and application of a sequence will be explained below to solve the above problem. The first explanation is a method of generating a sequence by changing the maximum meaning bit (MSB) of the initial value of a golden sequence. When a golden sequence is used to generate a random sequence, the 14 bits from the MSB are changed to a suitable value to equalize the ratio of "〇" to "1" contained in the initial value of the second lfsr. Because the cell service area ID, the sub-frame number, and the OFdM symbol number may cause the king to be "0" again in some cases, so the remaining 14 bits will be changed to a value of 18 200947988 to define A gold sequence with good PAPR characteristics. If a gold sequence is used, the resulting random sequence is determined based on the initial values. Therefore, it is important to set these initial values to produce a sequence with good PAPR. In one embodiment, the 14 bits from the MSB may all be set to "1". This prevents the initial values of the gold sequence from being set to "0". Therefore, the PAPR characteristics can be prevented from being deteriorated. The system φ shown in Table 2 is PAPR when all 14 bits from the MSB are set to "0". Table 3 shows the PAPR when all of the 14 bits from the MSB are set to "1". Table 2 and Table 3 show, based on the number of RBs (that is, 6, 12, 25, 50, and 100), the peak value when the reference signal used is the base sequence, which is based on the cell service area ID. The subframe number and the OFDM symbol number are generated in different ways by setting 17 bits from the LSB of the gold sequence generator. ❹ [Table 2] Number of RBs MSB LSB Point peak PAPR 6 00000000000000 10000110000100110 1.06 1.89 12 00000000000000 10000011010110011 1.33 2.36 25 00000000000000 00000000000000000 2.18 3.71 50 00000000000000 00000000000000000 5.16 8.81 100 00000000000000 00000000000000000 10.60 18.10 19 200947988 [Table 3] Number of RBs MSB LSB spike Value PAPR 6 11111111111111 10110000011101000 0.93 1.66 12 11111111111111 10110101111110010 1.28 2.28 25 11111111111111 10110110110110110 1.53 2.61 50 11111111111111 10010100100100100 1.87 3.19 100 11111111111111 00000000000000010 2.49 4.25 As shown in Table 2 and Table 3, when 14 bits from the MSB are all set to The case where the PAPR at "0" is better than the case where all 14 bits from the MSB are set to "1". In another embodiment, the 14-bit from the MSB may be set to a sequence of bits that can be cyclically mapped onto a QPSK constellation. The sequence values initially output from the gold sequence generator are the same as the initial values. Therefore, when the initial values are evenly arranged in the four symbol positions on the QPSK cluster, the modulated symbols of the generated random sequence can be prevented from being concentrated on a particular QPSK modulation symbol. The bit sequence to be cyclically mapped in the QPSK modulation shown in Fig. 12 is set as an example of the initial value. Assume that the bit sequences "00", "01", "11", and "10" on the QPSK cluster correspond to the modulation symbols 1, 2, 3, and 4, respectively. The bit sequence can be set such that the four modulation symbols appear uniformly in the 14 bits from the MSB. First, the first bit 20 200947988 sequence "00011110000111" will be defined as a modulation symbol appearing in the order of 1, 2, 3, 4, 1, 2, 3. In fact, the output of the gold sequence generator starts from the LSB. Therefore, the second bit sequence "11 10000111 1000" is defined by the inverse of the first bit sequence. The 17-bit from the LSB is set to the value proposed based on the cell service area ID, the subframe number, and the OFDM symbol number, and a QPSK modulation symbol is composed of 2 bits. Therefore, the third bit sequence φ "11000011110001" is generated by cyclically shifting the second bit sequence to the left by 1 bit. Among the 14 bits from the MSB, the nearest 17-bit bit from the LSB is randomly set, and the bit following the nearest bit (that is, the 19th bit from the LSB) ) will be mapped to a modulation symbol in units of 2 bits. Therefore, if a modulation symbol is output from the LSB, in the case of the third sequence, the modulation symbol is output in the order of 1, 2, 3, 4, 1, 2. 〇 Table 4 shows the PAPR characteristics based on the number of RBs when the 14-bit from the MSB is set to "110000111 10001". [Table 4] Number of RBs MSB LSB Point peak PAPR 6 11000011110001 10110000010110111 0.96 1.71 12 11000011110001 01100100010101001 1.31 2.33 25 11000011110001 01110101011011011 1.42 2.42 21 200947988 50 11000011110001 01111001101100100 1.70 2.90 100 11000011110001 00110000011001010 2.06 3.52 As shown in Table 4, when calculated from MSB The PAPR characteristic is improved when the 14-bit element is set to the proposed value. In another embodiment, various combinations of 14 bits from the MSB are proposed to improve PAPR characteristics. The 14-bit number from the MSB can be changed from "00000000000000" to "11111111111111" to find the value that has the best PAPR characteristics for all possible cases, which leads to great complexity. It is assumed herein that the number of RBs is 6, 12, 25, 50 or 100, and the reference signal used is a sequence having a length corresponding to the number of RBs. For each RB number, the 17-bit from the LSB is set differently based on the cell service area ID, the subframe number, and the OFDM symbol number. The reference signal is subjected to IFFT operation for OFDM modulation purposes, and the OFDM symbol is removed from the candidate value provided that the peak value of an OFDM symbol as a time domain signal exceeds a certain threshold. Table 5 shows the 14 bits from the MSB with the best PAPR characteristics for each RB number (i.e., 6, 12, 25, 50, and 100). [Table 5] 22 200947988 Number of RBs MSB LSB Point peak PAPR 6 00010001110001 00000001110000010 0.89 1.58 12 11001100100000 01000110110110101 1.10 1.96 25 01011111100110 00000011011100011 1.28 2.19 50 01100110010101 00010110100100101 1.42 2.42 100 00100001000101 01100100011010000 1.44 2.46 When the number of each RB is When the optimum value is used in the 14-bit from the MSB, the PAPR can be prevented from increasing due to the deviation. Table 6 shows the peak value and PAPR when 14 bits (i.e., "00010001110001") from the MSB in Table 5 are used for each RB number. The table shows that this optimum may not be optimal when using a particular number of RBs for a different number of RBs. [Table 6] Number of RBs MSB LSB Point peak PAPR 6 00010001110001 00000001110000010 0.89 1.58 12 00010001110001 01000011010101011 1.50 2.67 25 00010001110001 01000000010110001 1.51 2.58 50 00010001110001 10110011000011001 1.68 2.86 100 00010001110001 00010100111100111 1.75 2.99 23 200947988 To be selected as the optimum value, the important system To have uniform PAPR features in multiple RBs. When the optimum value is set to a value having a minimum peak sum of each RB among a plurality of values not exceeding a certain threshold, the 14-bit "001111011011〇〇" from the MSB is selected as best value. Table 7 shows the peak value and PAPR when 14 bits from the MSB in Table 7 (that is, "001 1 1 101 101 100") are used for each RB number. [Table 7] Number of RBs MSB LSB Point peak PAPR 6 00111101101100 01100011010011001 0.89 1.59 12 00111101101100 00001000101010101 1.14 2.03 25 00111101101100 00000111111001000 1.40 2.40 50 00111101101100 01001001010101000 1.55 2.65 100 00111101101100 10010011111001000 1.56 2.66 The PAPR characteristics are compared with the results of Table 5 (which can be Although it is considered to be the best value, although the deterioration is good, the results of the PAPR characteristics are better than those of Table 6 (which uses the 14-bit (that is, "00010001 110001") from the MSB). Therefore, the overall peak value and PAPR characteristics are uniform. Accordingly, the complexity may be lower than the difference depending on the number of RBs. 24 - 200947988 With 14 bits from the MSB, the advantage is that the memory size will be reduced. The method of improving the PAPR characteristics by setting the initial value of the second LFSR of the gold sequence generator has been described above. A method of improving a sequence of PAPR characteristics by setting an initial value of the first LFSR will be described below. In one embodiment, the initial value of the first LFSR can be determined to be a specific value. For example, a sequence of bits that are uniformly mapped by a modulation symbol on a QPSK cluster will be set to an initial value. If the bit sequence "00", "01", "11", "10" are reverse sorted (this is because the LSB is the first output in the golden sequence) and only repeats the mapping to 31 bits, the generated The value is "1111000011110000111100001111000". Table 8 shows the peak value and PAPR of the initial value of the first LFSR when the initial value of the first LFSR is Φ "11 11000011 110000111100001111000". Compared with the results in Table 2, PAPR has been greatly reduced. [Table 8] Number of RBs MSB LSB Point peak PAPR 6 00000000000000 00000011110010000 0.95 1.69 12 00000000000000 01110010110011100 1.16 2.07 25 200947988 25 00000000000000 01110001110001110 1.77 3.02 50 00000000000000 01100010011001001 1.86 3.18 100 00000000000000 10010111111011000 1.74 2.97 In another embodiment, the first LFSR The initial value can be set to the 1st complement of the initial value of the second LFSR. The initial value of the first LFSR shown in Fig. 13 is set as an example of the 1st complement of the initial value of the second LFSR. Even if the initial value of the second LFSR of the golden sequence generator is set to "0", the initial values of the first LFSR are all set to the 1st complement of the initial value of the second LFSR. According to this, a sequence having more random characteristics can be produced, and thus the PAPR characteristic can be prevented from being deteriorated. The initial value of the first LFSR shown in Table 9 is set as the result of the 1st complement of the initial value of the second LFSR.

[Table 9] Number of RBs MSB LSB Point peak PAPR 6 00000000000000 00000000000001000 0.97 1.72 12 0000000000(8)00 00010001010101010 1.27 2.26 25 00000000000000 00010101010101010 2.22 3.78 50 00000000000000 01110001110001110 2.98 5.08 100 00000000000000 00010100100000110 3.91 6.68 26 200947988 At the same time, to distinguish between cell service areas or UE The reference signal between the reference signals must have good correlation characteristics. As described with reference to FIG. u, in the initial value of the gold sequence generator, if only one cell service area ID is different and other values (that is, the subframe number and the 〇fdm symbol number) are the same, the generated Class-like random sequences may overlap in some cycles. This phenomenon occurs because only the value of 9 bits of the initial values differs among the 31 bits of the initial values. This can be resolved by taking into account the fact that only a portion of the sequence generated by © as a reference signal will be used. This is because even if a class-like random sequence of length Mux is generated (this sequence is called a base sequence), a sequence having a length Μ can be used depending on the number of RBs (this sequence is called a use sequence). Therefore, if the use sequence is selected based on the cell service area ID at a different offset from the generated base sequence, the problem can be solved because the sequence will be in a part of the period due to the almost identical initial value relationship. overlapping. A method of setting a sequence offset based on the cell service area ID will now be described. It is assumed that a base sequence having a length Mmax is generated by a gold sequence generator, that is, a 'base sequence c(i) (i = 0, l, ..., Mmax -1), and then a use sequence having a length Μ is used. . In this case, μ < Μ .

Ώι ει X Using the offset of the sequence (that is, using the starting point of the sequence) is set differently depending on the cell service area ID. 27 200947988 Figure 14 shows the offset of the available sequences based on a cell service area id. Here, the offset is placed in the base sequence of the length Mmax at a pitch N according to the cell service area ID, and the use sequence of the length] VI is selected. When the range of the underlying sequence is exceeded, the used sequence is cyclically shifted. From the base sequence c(i)(i = 0, l, .., Mmax-1), the sequence cu(i) (i = 〇, l, , M-1) can be expressed as follows: ❹ [ Public cu(i) = c((i + N · -1)) where '"mod" is the modulo operation, N is the offset interval, and NIDce11 is the cell service area ID. Although the same offset is defined herein for each cell service area id, which has only exemplary purposes, therefore, the offset of each cell service area ID can also be defined in different ways.使用 By changing the starting point of the used sequence according to the cell service area ID, even if the initial values are the same, the used sequence may be different. Therefore, the random characteristics can be secured' and the PAPR characteristics can be prevented from deteriorating. Equation 2 above can be expressed in the format of a reference signal of a 3GPP LTE system (wherein resources are allocated in RB units), as shown in the following formula 0 [Formula 3] 28 200947988 ~ (8) A 7^(1 - 2 _ C ( 2w))+ /:^(1 -2.c(2w + say w = 〇,l,...,2AC"DL -1 aK)=rW) m = 0,1,...,2 · ~ ι speak ' =O + «) mod(2. A^, DL -1)

❹ where ns is the number of time slots in a radio frame, / is the number of OFDM symbols in a slot, ri ns is a reference signal sequence, and ^, DL is the maximum number of rb 'm is the reference signal sequence The index, ~ is the index used to use the - part of the reference signal sequence, Nr is strictly the number of cents used, α υ (Ρ) is used as the reference symbol of the p-th antenna 埠 at the time slot ns The symbol, k is the heart transmission - the subcarrier index of the reference signal, and the interval 丨 is the starting point based on the cell service area ID ~ (m) may be a basic sequence ~ (m,) may be a use sequence . The map shown in Fig. 15 is based on the basic sequence in use in which the cell service area m is cyclically shifted. - a base sequence having a length Μ _ (that is, the base sequence c(1) (Bu (M, .., U)) is generated by a gold sequence generator. Then, the amount of cyclic shift is determined according to the cell service area m N. Then, the base sequence is cyclically shifted by the cyclic shift amount 。. In this example, the starting point of the sequence can be used to be placed at the same position. From the base sequence c(1)(4), 1, .., The following formula can be used to indicate the use sequence cu(i) (i = 0, l, ···, Mi): 29 200947988 [Formula 4] cshift ((z + ^' ^id11) m〇d(Mmax -1) = c(i) cu(i) = cshiJi(i) where cshift(i) is the sequence obtained by cyclically shifting the base sequence by the cyclic shift amount n. φ Equation 4 above can be used in the 3GPP LTE system (where the resource is allocated in RB units) is expressed in the format of the reference signal, as shown in the following formula 0 [Formula 5] r, '"s ^ = V2 ^ ~ 2 +J^2^~ 2 C( 2W +m = 0^2N!^i'DL ~l akj =%s(^) ® m = 0,lv",2.iC-l m,= (m + ^Zy^ +N^_N^)m 〇d{2.N^, DL _1} In another embodiment, when a sequence of random sequences is generated by a gold sequence generator Some sequences that are just beginning to be generated may be excluded. Sequences with a length of Nc may be removed from the gold sequence that was originally generated' and a subsequence sequence may be used as the reference signal sequence. The sequence that begins to be produced has a large effect, and thus 30 200947988 can prevent deterioration of PAPR characteristics caused by the same initial value. This can be expressed by the following formula. _ [Formula 6] c' (/) = c(i + Nc) Equation 6 above can be expressed in the form of Equation 1 above, which is shown in the formula below ^ [Formula 7] c{i) = (x(/ + Nc) + y(i + Nc)) mod 2 x(i + 31) = (x(z + 3) + x(i)) mod 2 y(i + 31) = (j;(/ + 3) + y(i + 2) + y(i + 1) + y (i)) The mod 2 value Nc can be set to a sufficiently random length so that the resulting class-like random sequence is not affected by the initial value. For example, the value Nc can range from 1500 to 1800. 7 can be represented by the format of the reference signal of the 3Gpp LTE system (where the resources are allocated in RB units) using the class-like random sequence c(i), as shown in the following formula [Equation 8] 31 200947988 ri, n Sc(2m)) c(2m +1)), m = -1 4Pl = rl, ns(^) m = 〇X...,2. -1 + -N^ Now explain the generated class between random sequences Interrelated characteristics.类 The class-like random sequence g(d) generated by using two m-sequences X(D) and Y(D) is represented by a non-faceted multiple form. [Formula 9]

GiD) = cQ+cxD^c2D2+... G〇D) := Ζφ) Θ r〇D) ® where 'the first m-sequence X(D) is L(9) (9), and the second 4th column 〇(〇) Let g2(D) be the primitive polynomial used to generate X(1)) and Y(D) and be defined as follows. [Formula 10] Private C〇) = i+zr3+zr31 g2 (D) = 1 + /)-1 + D~2 + D~3 + D~31 32 200947988

Ii(D) and I2(D) are initial values for generating X(D) and Y(D) and are defined as follows. [Formula 11] MD) = 1 12(D) = I(CELLID) ® I(Nsf, D9 Here, I(CELLID) is the initial value according to the cell service area ID CELLID, and I(Nsf)D9 is based on the time The number of slots and the initial value of the number of OFDM symbols. In a synchronous environment with the same timing between multiple cell service areas, adjacent cell service areas will have the same number of slots and the same number of OFDM symbols. When the number of slots and the same number of OFDM symbols, the correlation between the random sequences of the classes generated in the two adjacent cell service areas having different cell service areas IDCELLID1 and CELLID2 is obtained by the following formula [Equation 12] ] 33 200947988 G / D) ten G2 〇 D) = 尤 (9) ten ^ (9) ten fork (9) ten! ^) KD) 072 (D) = h, celn (DV g (_I2, cell2 (D) / g (D) = [ / ( C£ZZ/Z)1)Ten J(A^)D9]/g(i))Ten[/(CEZX/£>2)T/(i\^)Z)9]/g(Z)) =IiCELLim)/ giD,®I(J^)D9 ί g(D)®I{CELLID2)/ g{D)®I{Nsf)D9 / g(D) =I(CELLIDV)/ g(D)® IiCELLID2) / g(D) The above formula shows that the correlation property depends only on the cell service area ID. Since the correlation characteristics between the cell service areas are not changed by the number of time slots © and the number of OFDM symbols, it is difficult to obtain a sequence having good correlation characteristics in this method. When a modulation sequence (which consists of a modulation symbol obtained by performing QPSK modulation on a generated random sequence) is used to represent two cell service regions by Rl[n] and R2 [η], respectively, The isomorphic sequence can be expressed by the following formula: ® [Formula 13]

Rl[n] = S[2n]Xl[2n] + jS[2n + l]Xl[2n +1] R2[n] = + jS[2n + l]X2[2n +1] where S[n] A cell-serving region-dependent sequence that is dependent on a sub-frame number and an OFDM symbol number, and Xl[n] and X2[n] are cell service region-specific sequences obtained from each cell service region ID. The correlation between the above sequence Rl [η] and R2 [η] can be obtained by the following formula: 34 200947988 [Formula 14] R\[n]R2[n]* = (S[2n]Xl[2n] + jS[2n + 1]X1[2« + l])(S[2n]X7[2n] + jS[2n + \]X2[2n +1]) * =Zl[2n]X2[2«] * +Xl[2n + l]X2[2n +1] * + j(S[2n + \]X\\2n +1]5[2«] * X2[2n] * -S[2n + \]X2[2n + l]5 [2n] * X\[2ri\*) where ()* denotes a complex conjugate. The correlation between the two modulation sequences Rl[n] and R2[n] shows that there is a common sequence component of the cell service area changed by the number of sub-frames and the number of OFDM symbols, and there is no change in the Q ϋ axis. And the cell service area common sequence component is removed in the I axis. Therefore, it is difficult to obtain good interrelated characteristics between cell service areas. Accordingly, the present invention proposes a method for improving the correlation characteristics between the generated random sequences of classes. In a specific embodiment, the starting point of the used sequence may vary depending on the number of subframes and/or the number of OFDM symbols. Figure 16 shows the starting point of the used sequence according to the number of sub-φ frames and/or the number of OFDM symbols. A long-range random sequence is generated according to each cell service area ID. According to the number of subframes and the number of OFDM symbols, a plurality of basic sequences capable of supporting the maximum number of RBs are obtained from the long-range random sequence, each of which Both have a length Mmax. A sequence of lengths of Μ is obtained from a base sequence, which is used to transmit a true reference signal. Accordingly, the correlation characteristics of the reference signals between the cell service areas can be improved. 35 200947988 The reference sequence can be expressed in the format of a reference signal of a 3GPP LTE system (in which the resources are allocated in rB units), as shown in the following formula [Equation 15] ri, n, (w) = (l - 2 · c(2m + /〇)+7 -ίτ (l - 2 · c(2m +1 + Γ)) /f = 4A/^DL . (^Cb · «s + 0 and w = 0,1, ..., 2A^, DL -1 where '113 is the number of time slots in a radio frame, / is the number of OFDM symbols in a slot, ri ns is a reference signal sequence, and #^^ is the maximum number of RBs m is the index of the reference signal sequence, and NsymbDL is the number of OFDM symbols included in the one-time slot. The basic sequence c(i) generated by the golden sequence generator will be NiDeell+l at the beginning of each OFDM symbol. Initialization. In another embodiment, the initial values used to generate the base sequence may be changed to improve the correlation characteristics, provided that the number of subframes and/or the number of subframes in the same synchronization environment between multiple cell service areas is If the number of OFDM symbols is the same, the initial values of the number of subframes and/or the number of OFDM symbols between the cell service areas will be the same, which may cause defects. Correlation characteristics. In addition, in the non-synchronous environment, the transmission time difference between adjacent cell service areas must be taken into account, so that the initial values are not consistently the same as 36 200947988. The initial values can be based on the cell service area. The number of subframes and/or the number of OFDM symbols varies in different ways. For example, the first cell service area can be configured to increase or decrease the initial value as the number of OFDM symbols increases, second The cell service area can also be configured to increase or decrease the initial value as the number of OFDM symbols increases. For example, the cell service area with the cell service area ID CELLID1 will be configured to have an initial value along with the OFDM symbol. In addition, the cell service area with the cell service area ID CELLID2 is configured to increase the initial value by n+1 as the number of OFDM symbols increases by 1. The number of OFDM symbols can be expanded by the radio frame unit. , instead of being in a sub-frame or a time slot, therefore, when the number of OFDM symbols changes, the initialization changes will be different. If each sub-frame has Nsym OFDM symbols Then, k*Nsym+q can be used to represent the qth OFDM symbol number of the kth subframe of a radio frame φ. In a system in which the number of OFDM symbols included in each subframe is different, it may be defined. The maximum number of OFDM symbols per subframe is Nsym,max. In this case, the number of qth OFDM symbols of the kth subframe of the radio frame may be represented by k*Nsym,max+q. The above reason allows each OFDM symbol to have a unique number of OFDM symbols in a radio frame. The gold sequence generator can increase or decrease the initial value of a m-order 37 200947988 column by a predetermined interval as the number of OFDM symbols increases. For example, a cell service area with a cell service area ID of CELLID1 allows the initial value to be increased by a predetermined value (e.g., CELLID1 or CELLID1 + 1) as the number of OFDM symbols increases by one. Furthermore, the cell service area with the cell service area ID of CELLID2 allows the initial value to be increased by a preset value (e.g., CELLID2 or CELLID2 + 1) as the number of OFDM symbols increases by one. However, this may be a problem when the cell service area IDs between cell service areas differ by about two times. For example, if CELLID1=5, CELLID2=11, and the default values are CELLID1+1 and CELLID2+1, then the initial values added when the number of OFDM symbols increases are 6 and 12, respectively. The difference in times. This can be represented in a binary format where one bit is shifted. This is because the binary format of 6 is "0110"' and the binary format of 12 is "11 00". When shifting one bit, if QPSK is used, the correlation feature will be due to the first cell service area. The reference Ο signal is degraded by the overlap relationship between the I-axis component of the signal and the Q-axis component of the reference signal of the second cell service area. Therefore, when the number of OFDM symbols and/or the number of sub-frames increases, it is necessary to set the initial values so that the increment of one cell service area is not twice the increment of another cell service area. This can be easily achieved by increasing or decreasing the initial value by an odd number when the number of OFDM symbols and/or the number of sub-frames increases. For example, the cell service area can be made when the number of OFDM symbols increases or decreases. The initial value of the gold sequence generator with ID η is increased by 38 200947988 plus or minus (2n+1) times. This can be expressed in the format of a reference signal of a 3GPP LTE system in which resources are allocated in RB units, as shown in the following formula. [Formula 16] ri,ns (w) = -^=(1 - 2 · c{2m))+ j~^_-2.c(2m + 1)), m = _χ Here, ns is a radio The number of time slots in the frame, / is the number of OFDM symbols in the time slot 'r丨, ns is a reference signal sequence, and ^, DL is the maximum number. In this case, the sequence generator can be initialized with the following formula: [Formula 17] cinit = 29 ·{Γ + 1).(2-N^1 +1)+ N^1 where '" is defined as 8 ns + / and is the number of OFDM symbols in a radio frame. At the same time, the correlation between the 'class-like random sequences will be based on the binary addition result used to generate the initial values of the two kinds of random sequences, as shown in the following formula. [Formula 1 8] 39 200947988 (^φ) 十(72〇0) = Ζφ) 十 1; (D) 十 Z〇D) 十 y2〇D) = Yx{D)®Y2{D) = hceln(D ) /g(D)®I2iCell2(D)/g(D) = (h,celn(D)®I2,cell2(D))/g(D) Therefore, if the number is changed according to each OFDM symbol number When the initial values are generated to generate the random sequences of the classes, a good correlation characteristic is obtained when the binary addition result of the initial values of the individual cell service areas is changed by 0 as the number of OFDM symbols changes. This metaphorizes the initial value of the first cell service area CiniJlM, /) and the initial value of the second cell service area cinit(n2, /) will change when the number of OFDM symbols/change. Here, it is the cell service area ID of the first cell service area, and n2 is the cell service area ID of the second cell service area. In addition, based on QPSK modulation, when and with. (9), /) Ten (2_Cm («2, 〇) can be obtained according to the number of OFDM symbols / can obtain good correlation characteristics. ❿ Figure 17 shows the initial value of a gold sequence generator. The 31 bits in the initial value of the two LFSRs are divided into two regions (that is, the #1 region and the #2 region). Each region is composed of 14 bits. The #2 region is located on the LSB side. Any value can be Set to the remaining 4 bits from the MSB. Each of the #1 and #2 areas contains a binary sequence of cell service area IDs. In the #1 area, the binary sequence of the cell service area IDs The first cyclic shift mi is cyclically shifted according to the number of OFDM symbols. In the #2 region, the binary sequence of the cell service area ID will be shifted according to the number of OFDM symbols / 40 200947988 - for example, in In the #1 region, the fine binary sequence may be cyclically shifted by /mi, and the binary sequence of the cell service area ID in the #2 region tb may be cyclically shifted by the shift. /m2. By dividing the initial values into two regions and by incorporating a binary sequence of cell service region IDs (in each region, a different cyclic shift is used for it) , According to the number of OFDM symbols can / be modified

If the right bl indicates the size of the #1 area and h indicates the size of the #2 area, then the size of the bl=b2=14°#1 area and the #2 area can be arbitrarily defined within the range of the initial value. In order to increase the production cycle of a golden sequence, 匕 and 匕 can be set to be prime. In addition, mi and bl, and % and b2 can also be set to be prime. This can be expressed in the format of the reference 彳s number of the 3GPP LTE system (where the resources are allocated in RB units), as shown in the following formula:

Cyclicly shifted cell service area ID

[Equation 19] rl, ns (w) = ^=r(l-2·c(2m))+ c(2m + 1)), m = _ j where ' at the beginning of each OFDM symbol ~ t = 214 · α513(2< +1,11./,) + 0514(2<丨+1,3·/,) "=29 4(2./)/i〇" , and CSb(M,a) = (2amodb -M)mod26 +[(2amodft .M)/2b\ .,. / is the number of 〇FDM symbols in a radio 200947988 frame, CSb(M a) is a cyclic shift function and the L" table does not provide a floor function smaller than the largest integer of x. Although the proposed sequence is described for the downlink link reference signal of 3Gpp lte/lte_a, the proposed sequence can also be used for the uplink reference signal. Furthermore, although the PAPR and inter-correlation properties are described herein with respect to reference signals for cell service regions, these features are equally applicable to reference signals between UEs and/or between antennas. The reference signal used by the sequence derived by ® may be a common reference signal for the cell service area or a UE-specific reference signal. Figure 18 is a flow chart showing a method of transmitting a reference signal in accordance with an embodiment of the present invention. This method may be implemented by a transmitter. The transmitter may be part of the BS when transmitting the downlink reference signal, or may be part of the UE when transmitting the uplink reference signal. In step S510, a reference signal sequence is generated. The reference signal sequence © can be defined by the following formula. [Formula 20] = c(2m))+j^=(l-2-c(2m +1)), w = 〇,1”..,2_?\^See_ι Here, ~ is a radio The number of time slots in the frame, / is the number of OFDM symbols in the slot, r 丨, ns is a reference signal sequence, and is the maximum number of rb. The class-like random sequence c(i) can be defined by Equation 7 above. 200947988 Here, the m-sequence x(1) can be initialized with an initial value represented by χ(〇) = ι, x(i)=〇, i=l, 2, ..., 30; and the m-sequence (y) can be Initialization is performed using an initial value obtained from (2NIDcell+l), where NIDce11 is the cell service area ID. The initial value of the m-sequence y(i) may vary with the number of 〇fdM symbols/change. Therefore, the m-sequence y The initial value of (i) can be obtained from /(2NIDeell + l). In step S520, some or all of the reference signal sequence will be mapped to at least one RB. One RB may contain 12 subcarriers. For the cell service area common reference signal, the two modulation symbols in the reference sequence can be mapped to two subcarriers within one RB. If it is a UE-specific reference signal, the reference signal sequence The three modulation symbols can be mapped to three subcarriers within an RB. In step S530, the reference signal is transmitted using the rb. The proposed reference signal sequence provides improved PAPR and correlation. Therefore, the transmit power efficiency of the transmitter can be improved, and the receiver can have higher detection performance. Figure 19 is a block of a transmitter and a receiver for performing a method of transmitting and receiving a reference signal. The transmitter 800 includes a data processor 810', a reference signal generator, and a transmission circuitry 83A. The data processor 810 processes an information bit to generate a transmitted signal. The reference signal generator 82 generates a reference signal. The reference signal generation of the first map can be implemented by reference signal generator 820. Transmission 43 200947988 The circuit system 830 transmits the transmission signal and/or the reference signal. Receiver 900 includes a data processor 91A, a channel evaluator 920', and a receiving circuitry 93A. The receiving circuitry %〇 receives a reference signal and a received signal. The channel evaluator 92 uses the received reference signal to evaluate a channel. The data processor 91 uses the evaluated channel to process the received signal. Although the proposed sequence is used as a reference signal in the examples of the foregoing specific embodiments, the proposed sequence can also be applied to various signals. For example, the proposed sequence can be used for scrambling codes, synchronization signals, preambles, mask codes, and the like. The base sequence of Equation 20 can be generated based on the class-like random sequence c(i) of Equation 7. The m-sequence y(i) of the class-like random sequence c(i) can be initialized using an initial value obtained from (2NiDcell+i), where N^cell is the cell service area ID. The base sequence can be applied in conjunction with a target signal or target. Applying the base sequence to match the target signal or the target code may use a part or all of the reference signal sequence column according to the allocated resource or length (or large) of the target signal or the target code. The applied sequence will be transmitted. The transmitted sequence can be used by the receiver for a variety of applications. The invention can be practiced using hardware, software, or a combination thereof. In the hardware implementation mode, the present invention can be implemented by using one of the following: an application specific integrated circuit (ASIC), a digital signal processor (Digitai signai pr〇cess〇r, dsp), and a program. Programmable logic device (PLD), can be designed with a field programmable gate array (FPGA), processor, controller, microprocessor, other electronic unit, or a combination of the foregoing. Used to implement the aforementioned functions. In the soft body mode of operation, the present invention can be implemented using a module for performing the aforementioned functions. The software can be stored in the memory unit and executed by the processor. Various components that are generally known to those skilled in the art can be used as the memory unit or processor. Although the invention has been particularly shown and described with reference to the exemplary embodiments of the embodiments of the invention Spirit and scope. The exemplary embodiments are to be considered in all respects as illustrative and not limiting. Therefore, the scope of the present invention is not defined by the embodiments of the present invention, but is defined by the scope of the appended claims. All the differences within the scope are considered to be encompassed in the present invention. [Simple description of the diagram] Figure 1 shows a wireless communication system. The structure of the radio frame in 3gpp LTE shown in Fig. 2 is shown. Figure 3 shows an example of a resource grid for a downlink time slot. The exemplary structure of the downlink subframe is shown in FIG. Figure 5 shows an exemplary structure of the reference signal when the bs uses an antenna. Figure 6 shows an exemplary structure of the downlink common reference signal when the BS uses two antennas. Figure 7 shows an exemplary structure of the downlink common reference signal when bs uses four antennas. An example of a gold sequence generator is shown in FIG. The setting of the initial value of the second LFSR is shown in Fig. 9. e Figure 10 is a diagram showing the relationship between the size of a reference signal and any information when the initial values of the second LFSR are all set to "〇". Figure 11 shows the problem caused by the initial value of a golden sequence in a multi-cell service area environment. The bit sequence to be cyclically mapped in the QPSK modulation shown in Fig. 12 is set as an example of the initial value.初始 The initial value of the first LFSR shown in Fig. 13 is set as an example of the 1st complement of the initial value of the second LFSR. Figure 14 shows the offset of the available sequence based on a cell service area id. Figure 15 shows the starting point of the used sequence according to the number of sub-frames and/or the number of OFDM symbols, according to the basic sequence in use, which is cyclically shifted by a cell service area iD. . 46 200947988 Figure 17 shows the setting of the initial value of a gold sequence generator. Figure 18 is a flow diagram of a method of transmitting a reference signal in accordance with an embodiment of the present invention. Figure 19 is a block diagram of a transmitter and a receiver for performing transmission and reception of reference signals. [Main component symbol description] 1 〇 wireless communication system 11 base station 12 user equipment 1 5 a cell service area 810 data processor 820 reference signal generator 830 transmission circuit system 900 receiver 15b cell service area 15c cell service area 800 Transmitter 910 data processor 920 channel evaluator 930 receives circuitry ❹ 47

Claims (1)

200947988 VII. Patent application scope: κ - in the no-material wire towel transmission reference (4) time method, the method comprises the following steps: generating a reference signal sequence r, defined by n, (m) 72^1 2, C (2/W^+-;,^(1-2-c(2/n + l)), w = 0,1,...,2^-dl-1 where & is a radio frame The number of slots in the hour, / is one 正交 The number of orthogonal frequency division multiplexing (〇FDM) symbols in the time slot is a maximum number of resource blocks (RB), wherein a random sequence e(1) is obtained by one utilization (2; < + 1) The initial value is generated by an initialized gold sequence generator, wherein 'is a cell service area identification code; a portion or all of the reference signal sequence is mapped to at least one RB; and a reference signal is transmitted in the at least one RB. 2. As stated in the method of claim 1, wherein a random sequence c(i) is defined by: Φ) = (x(i + Nc) + y(i + Nc)) mod 2 x (i + 31) = (x(i + 3) + x(i)) m〇d 2 y(i + 31) = (y(i + 3) + y{i + 2) + yii + l) + y(i)) m〇d 2 where 'x(i) and again (1) are m sequences, and Nc is a constant. The method of claim 2, wherein the m sequence χο) is initialized with x(0) = l, x(i)=〇, i=1 2···., 3 0, and the sequence is πι (y) is initialized with the initial values of the phases. 48 3. 200947988 4. The method of claim 2, wherein Nc is a value ranging from 1500 to 1800. 5. The method of claim 1, wherein the initial values change as the number of OFDM symbols changes. 6. The method of claim 5, wherein the initial values are obtained using /. 7. The method of claim 1, wherein the initial value of © is 31 bits. 8_ The method of claim 1, wherein one rb includes 12 subcarriers in the frequency domain. 9. The method of claim 8 wherein the two modulation symbols in the reference signal sequence are mapped to two subcarriers in the -RB. 10. The method of claim 17, wherein the reference signal is a cell service area common reference signal or a user equipment (UE) specific reference signal. 11. A transmitter comprising: a reference signal generator for generating a reference signal; and a transmitting circuit system for transmitting the reference signal, wherein the reference signal generator generates a reference defined by The signal sequence is used to generate the reference signal: 49 200947988 ^(-) = ^(1-2.(2,))+y^(l_2.c(2w + 1))5 w = 〇>15 where ns is - The number of slots in the radio frame, / is the number of FDM symbols in the slot, and W is the maximum number of RBs -, where the class-random sequence c(1) is used by one (2<ι + ι) The initial value obtained is initialized by the gold sequence generator to generate 10 of the cell service area identification code; and a portion or all of the reference signal sequence is mapped to at least one RB. 12. The transmitter of claim 3, wherein the random sequence c(i) is defined by: c(〇= (x(i + Nc) + y{i + Nc)) Mod 2 x(i + 31) = (jc(/ +3) + x(j)) mod 2 y(i + 31) = (X/ + 3) + y(i + 2) + y(i + 1 + ^(/)) mod 2 where x(i) and y(i) are m sequences, and Nc is a constant. 13. A receiver comprising: a receiving circuitry for receiving a reference signal and a received signal; a channel evaluator for evaluating a channel using the reference signal; and a data processor for utilizing The channel processes the received signal, wherein the reference signal is generated based on a reference signal sequence 50 200947988 defined below, ri,n, (w) = -^=(1 - 2 · c(2/« ))+(l - 2 · c{2m + 1)), m = 〇χ..,92Ν^ -1 where ns is the number of time slots in a radio frame, / is one hour • an OFDM in the slot The number of symbols, and ^ double is a maximum number of RBs, wherein a random sequence c(i) is generated by a gold sequence generator initialized by using (2^^ + 1) to obtain the initial value of _, where is the cell Service area identifier. 14. The receiver of claim 13, wherein the random sequence c(i) is defined by c(0 = (λ(ι + Nc) + y(i + iVc»mod 2 x (i + 31) = 〇; (z_ + 3) + work"_d 2 w + 3 〇 = CK*· + 3) + less (/ + 2) + 〆 / +1) + _y(0)mod 2 x(i) and y(i) are m sequences, and Nc is a constant.