CN103095625B - Scramble initial value collocation method - Google Patents

Abstract

The present invention provides a method for configuring the initial value of the scrambling code, which is used in a system with discontinuous working frequency bands, including: when the initial value of the scrambling code needs to be set for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30, initialize the first m-sequence x ₁ () used to generate the scrambling code sequence, according to the sub-band index number and cell identity of the sub-band Number, initialize the second m-sequence x ₂ () used to generate the scrambling code sequence. The invention can reduce the peak-to-average ratio of the time-domain signal of the system with discontinuous frequency spectrum bandwidth.

Description

A configuration method of initial value of scrambling code

technical field

The present invention relates to the resource configuration technology in the mobile communication system, in particular to a method for configuring the initial value of the scrambling code.

Background technique

The scrambling code can make the digital transmission system transparent to various digital information, that is, to randomize the binary digital information, so that the signal spectrum can be diffused and kept stable. In the 3GPP Long Term Evolution (LTE) system, a scrambling code is designed for each physical channel, and the characteristics of the scrambling code are used to reduce mutual interference of signals between cells. The downlink control format indication channel (PCFICH) is taken as an example. On each subframe, CFI (control format indication) is used to indicate the number of OFDMs occupied by the PDCCH on the subframe. CFI follows the table 5.3.4- 1 for channel coding 32 bits.

The encoded bit blocks b(0),...,b(31) are scrambled using a cell-specific scrambling code sequence to form a scrambled bit block Right now $\tilde{b}\left(i\right)+(b\left(i\right)+c\left(i\right))\mathrm{mod}2$

Among them, the scrambling sequence c(i) is generated using a Gold sequence with a length of 31, and the pseudo-random sequence c(n) with a length of M _PN , n=0, 1,..., M _PN -1 is defined as

c(n)=(x ₁ (n+N _C )+x ₂ (n+N _C ))mod 2

x ₁ (n+31)＝(x ₁ (n+3)+x ₁ (n)) mod 2

x ₂ (n+31)＝(x ₂ (n+3)+x ₂ (n+2)+x ₂ (n+1)+x ₂ (n)) mod 2

Where N _C =1600, the first m sequence x ₁ () is initialized by x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30, the second m The sequence x ₂ () is given by Initialize, the initialization value c _init of the sequence is initialized according to the following formula at the beginning of each frame:

Among them, n _s represents the time slot number of a radio frame, Represents the cell ID.

Since each cell has only one PCFICH per subframe and only occupies 4 REGs, in practical applications, PCFICHs of different cells may be mapped to the same resource position. In this case, by using different scrambling codes, The purpose of reducing PCFICH mutual interference between cells can be achieved.

The 3GPP Long Term Evolution (LTE) system downlink control format indication channel is allocated on the entire system bandwidth, and there is only one PCFICH channel in a subframe. Therefore, in the above-mentioned existing PCFICH scrambling code sequence generation method, setting the initial value of the scrambling code only considers The time slot number and physical layer cell ID in the radio frame are used to reduce the mutual interference of control signals between cells through scrambling.

The private network communication system usually occupies discontinuous spectrum bandwidth, and each 25kHz is a subband. On the eNodeB side, each subband has a PCFICH channel, occupying the same resource location, and each subband performs IFFT independently to generate a time domain signal. After being modulated to the corresponding carrier frequency, superposition in the time domain is performed, and then sent out through the antenna port.

In practical applications, it often occurs that the codeword information carried by the control channels on multiple subbands is the same. At this time, if the above-mentioned scrambling code generation method for the LTE control channel is used, the same scrambling sequence will be generated. In this way, before IFFT conversion, multiple sub-bands will generate the same frequency domain signal (f ₁ , f ₂ ... f _N ), then after IFFT, filter filtering, and modulation to their respective carrier frequencies, the synthesized The time domain signal signal can be approximated by the following formula:

$\mathrm{<span\; class="notranslate">\; signal</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; ifft</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; )</span>}$

$<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; ifft</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; ifft</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; TotalSubBand</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; )</span>}$

$<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; ifft</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1,2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; TotalSubBand</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; )</span>$

Among them, TotalSubBand is the number of subbands.

It can be seen from the above formula that when the number of subbands is large, it will cause a high peak-to-average ratio (PAPR), which will affect the quality of signal transmission and reception.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method for configuring an initial value of a scrambling code, which can reduce the peak-to-average ratio of time-domain signals in a system with discontinuous spectrum bandwidth.

In order to achieve the above object, the technical scheme proposed by the present invention is:

A method for configuring an initial value of a scrambling code, which is used in a system with discontinuous working frequency bands, comprising the following steps:

When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30, initialize the first scrambling code sequence for generating the scrambling code sequence An m-sequence x ₁ (), initialize a second m-sequence x ₂ () for generating a scrambling code sequence according to the subband index number and the cell identification number of the subband.

In summary, the method for configuring the initial value of the scrambling code proposed by the present invention introduces the subband number when generating the scrambling code, and sets different initial values of the scrambling code sequence for different subbands, so that different scrambling code sequences can be generated on this basis. The code sequence randomizes the time-domain data on multiple subbands to achieve the purpose of reducing the peak-to-average ratio.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments.

The core idea of the present invention is: for a system with discontinuous working frequency bands, when setting the initial value of the scrambling code for the control channel and the traffic channel, the sub-band number is introduced to generate different scrambling code sequences for different sub-bands, so that multiple The time-domain data on each subband is randomized, so that when modulated to their respective carrier frequencies for combination, the peak-to-average ratio of the resulting time-domain signal can be reduced.

Embodiment 1 of the present invention mainly includes the following steps:

When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30, initialize the first scrambling code sequence for generating the scrambling code sequence An m-sequence x ₁ (), initialize a second m-sequence x ₂ () for generating a scrambling code sequence according to the subband index number and the cell identification number of the subband.

In the above method, the second m-sequence x ₂ () used to generate the scrambling code sequence is initialized by introducing the sub-band index number, so that different scrambling code sequences can be generated for different sub-bands.

In practical applications, after the first m-sequence x ₁ () and the second m-sequence x ₂ () are obtained by using the above method, those skilled in the art can generate the corresponding scrambling code sequence according to the existing method, which will not be repeated here repeat.

Specifically, the following several methods can be used to obtain the second m-sequence x ₂ ().

Method 1: Follow the $c_{\mathrm{init}}=(2*\mathrm{SubBandIndex}+1)\&times;({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where SubBandIndex is the subband index number, is the cell identification number.

Method 2: Follow the $c_{\mathrm{init}}=(2\&times;\mathrm{SubBandIndex}+{\mathrm{no}}_{\mathrm{the\; s}}+1)\&times;({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, wherein, SubBandIndex is a subband index number, n _s is the subframe number of the wireless frame where the channel of the subband is configured, is the cell identification number.

Method Three: According to $c_{\mathrm{init}}=(2{\&times;\mathrm{no}}_{\mathrm{RNTI}}+1)\&times;(2\&times;\mathrm{SubBandIndex}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where n _RNTI is a wireless network temporary identification number, SubBandIndex is a subband index number, is the cell identification number.

Method 4: According to $c_{\mathrm{init}}=(2{\&times;\mathrm{no}}_{\mathrm{RNTI}}+1)\&times;(2\&times;\mathrm{SubBandIndex}+{\mathrm{no}}_{\mathrm{the\; s}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where n _RNTI is a wireless network temporary identification number, SubBandIndex is a subband index number, is the cell identification number, and n _s is the subframe number of the radio frame where the channel of the subband is configured.

Preferably, when the subband is the subband occupied by the Physical Control Format Indicator Channel (PCFICH), the Physical HARQ Indicator Channel (PHICH) or the Physical Downlink Control Channel (PDCCH), the above method 1 or method 2 can be used to obtain The second m-sequence x ₂ ().

Preferably, when the subband is a subband occupied by a Physical Downlink Shared Channel (PDSCH), the second m-sequence x ₂ () can be obtained by using the third or fourth method above.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A configuration method of an initial value of a scrambling code, which is used in a system with discontinuous working frequency bands, is characterized in that the method comprises the following steps: When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1,2,...,30, initialize the first scrambling code sequence used to generate An m sequence x ₁ (), according to the subband index number and the cell identification number of the subband, initialize the second m sequence x ₂ () used to generate the scrambling code sequence; Among them, according to $c_{\mathrm{init}}=(2*\mathrm{SubBandIndex}+1)\&times;({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where SubBandIndex is the subband index number, is the cell identification number. 2. The method according to claim 1, wherein the subband is a subband occupied by a Physical Control Format Indicator Channel (PCFICH), a Physical HARQ Indicator Channel (PHICH), or a Physical Downlink Control Channel (PDCCH). 3. A configuration method of an initial value of a scrambling code, which is used in a system with discontinuous operating frequency bands, is characterized in that the method comprises the following steps: When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1,2,...,30, initialize the first scrambling code sequence used to generate An m sequence x ₁ (), according to the subband index number and the cell identification number of the subband, initialize the second m sequence x ₂ () used to generate the scrambling code sequence; Among them, according to $c_{\mathrm{init}}=(2\&times;\mathrm{SubBandIndex}+{\mathrm{no}}_{\mathrm{the\; s}}+1)\&times;({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, wherein, SubBandIndex is a subband index number, n _s is the subframe number of the wireless frame where the channel of the subband is configured, is the cell identification number. 4. The method according to claim 3, wherein the subband is a subband occupied by a Physical Control Format Indicator Channel (PCFICH), a Physical HARQ Indicator Channel (PHICH), or a Physical Downlink Control Channel (PDCCH). 5. A configuration method of an initial value of a scrambling code, which is used in a system with discontinuous working frequency bands, is characterized in that the method comprises the following steps: When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1,2,...,30, initialize the first scrambling code sequence used to generate An m sequence x ₁ (), according to the subband index number and the cell identification number of the subband, initialize the second m sequence x ₂ () used to generate the scrambling code sequence; Among them, according to $c_{\mathrm{init}}=(2\&times;{\mathrm{no}}_{\mathrm{RNTI}}+1)\&times;(2\&times;\mathrm{SubBandIndex}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where n _RNTI is a wireless network temporary identification number, SubBandIndex is a subband index number, is the cell identification number. 6. The method according to claim 5, wherein the subband is a subband occupied by a physical downlink shared channel (PDSCH). 7. A configuration method of an initial value of a scrambling code, which is used in a system with discontinuous working frequency bands, is characterized in that the method comprises the following steps: When it is necessary to set the initial value of the scrambling code for the subband, according to x ₁ (0)=1, x ₁ (n)=0, n=1,2,...,30, initialize the first scrambling code sequence used to generate An m sequence x ₁ (), according to the subband index number and the cell identification number of the subband, initialize the second m sequence x ₂ () used to generate the scrambling code sequence; Among them, according to $c_{\mathrm{init}}=(2\&times;{\mathrm{no}}_{\mathrm{RNTI}}+1)\&times;(2\&times;\mathrm{SubBandIndex}+{\mathrm{no}}_{\mathrm{the\; s}}+1)\&times;2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init , using the c _init , according to Initialize the second m sequence x ₂ () used to generate the scrambling code sequence, where n _RNTI is a wireless network temporary identification number, SubBandIndex is a subband index number, is the cell identification number, and n _s is the subframe number of the radio frame where the channel of the subband is configured. 8. The method according to claim 7, wherein the subband is a subband occupied by a physical downlink shared channel (PDSCH).