CN104734813A - Upstream pre-coding method based on rotary codebook for fixed electric power communication terminal - Google Patents

Abstract

The invention discloses an upstream pre-coding method based on a rotary codebook for a fixed electric power communication terminal. The upstream pre-coding method based on the rotary codebook for the fixed electric power communication terminal mainly comprises the four steps that first, a plurality of different but equivalent codebook sets are established simultaneously at a transmitting end and a receiving end and arrayed; next, channel estimation is performed at the receiving end according to a descending pilot signal; then, an optimal codebook is screened out from 2 <l> codebook sets by using a channel state at the receiving end, and the serial number of the optimal codebook is fed back to the transmitting end; finally, the transmitting end uses the serial number of the optimal codebook fed back by the receiving end to find the corresponding codebook, the codebook is used to perform pre-processing on sending data, and the data after the pre-processing are sent. The upstream pre-coding method based on the rotary codebook for the fixed electric power communication terminal adopts a plurality of the codebooks, default serial numbers are introduced, the capacity of the codebook can be virtually improved, and meanwhile the communication speed of the electric power terminal can also be increased.

Description

The uplink precoding method based on rotation code book of fixing power communication terminal

Technical field

The invention belongs to communication of power system field, particularly a kind of uplink precoding method based on rotation code book of fixing power communication terminal.

Background technology

Along with the expansion that intelligent grid is built, the demand of power business to reliability, fail safe improves constantly, and the construction of electric power wireless private network receives increasing concern.Intelligent grid adapted electric industry business terminal multi-point and wide-ranging and distribution dispersion, although optical fiber communication mode possesses the strong advantage of business transmittability, dispose difficulty of construction large, cost is high, cannot meet all standing to magnanimity adapted electric terminals.Along with the fast development of wireless broadband communication technology, as the means of supplementing out economy of the wired optical fiber communication of electric power, the tenability of radio communication to electric power adapted electricity side business is greatly improved, and increasing energy communication service is considered to use radio communication to carry.

Precoding technique mainly carries out preliminary treatment by the signal sent multiple antennas of transmitting terminal, thus controls the direction of launching beam.Precoding technique is relatively applicable to building and blocks less suburban environment, also may be used for the urban area circumstance in complexity.

For existing wireless power terminal communication, the number of antennas of the electric power terminal side of mimo system is 2, and in most cases electric power terminal is all fixing, this is for precoding technique, just can consider original single data stream to be conveyed through MIMO precoding technique to become two data flow and transmit simultaneously, thus improve the uplink communication speed of electric power terminal, more adequately and reasonably to utilize spatial channel resources.

Terminal in power communication system mainly comprises intelligent electric meter, smart-interactive terminal, intelligence switching center etc., they are by utilizing advanced ICT (information and communication technology), unified monitoring and management are carried out to household electricity equipment, the data such as the quality of power supply, household electricity information is gathered and analyzed, instructs user to carry out rational utilization of electricity, regulate electrical network peak load, realize intelligent interaction between electrical network and user.

Due in reality system, consider the expense of system, usually all adopt traditional codebook precoding technology, electric power system data transmission requirement cannot be met.

Summary of the invention

Technical problem solved by the invention is the uplink precoding method based on rotation code book providing a kind of fixing power communication terminal.

The technical solution realizing the object of the invention is: a kind of uplink precoding method based on rotation code book of fixing power communication terminal, comprises the following steps:

Step 1, create that K different but the size of equivalence is 2 at transmitting terminal and receiving terminal simultaneously ^lcodebook set, and it is arranged, wherein K, L are natural number;

Step 2, carry out channel estimating at receiving terminal according to descending pilot signal;

Step 3, utilize channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set, and this optimum code book sequence number is fed back to transmitting terminal;

Step 4, transmitting terminal utilize the code book sequence number of the optimum of step 3 gained, find corresponding code book, and utilize this code book to carry out preliminary treatment to transmission data, pretreated data are sent afterwards.

Compared with prior art, its remarkable advantage is in the present invention: (1) utilizes the capacity K of the raising code book that method of the present invention can be virtual doubly; (2) method of the present invention effectively can improve electric power terminal uplink communication speed.

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Accompanying drawing explanation

Fig. 1 is the up pre-coding system schematic diagram based on rotating code book.

Fig. 2 is that in the up pre-coding system based on rotation code book, random code word covers schematic diagram.

Embodiment

The uplink precoding method based on rotation code book of a kind of fixing power communication terminal of the present invention, comprises the following steps:

Step 1, create that K different but the size of equivalence is 2 at transmitting terminal and receiving terminal simultaneously ^lcodebook set, and it is arranged, wherein K, L are natural number; Create K difference but the size of equivalence is 2 ^lcodebook set put in order into:

$...,F_0^L,F_1^L,F_2^L,...,F_{K-1}^L,F_0^L,F_1^L,F_2^L,...$

Wherein for the code book corresponding to moment t=kT+nKT, and k=0,1,2, K-1, n are natural number, and T is the feedback interval of precoding.

Step 2, carry out channel estimating at receiving terminal according to descending pilot signal; At receiving terminal according to the de-scrambling method specifically adopting conjugate multiplication when utilizing down-bound pilot frequency signal to carry out channel estimating.

Step 3, utilize channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set, and this optimum code book sequence number is fed back to transmitting terminal; Utilize channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set specifically to comprise the following steps:

Step 3-1, determine the capacity C (F that channel corresponding to each code book can reach _i), formula used is:

C(F _i)＝log det(I+γ(HF _i) ^*(HF _i))＝log det(I+γF _i ^*H ^*HF _i)

Wherein, γ is signal noise ratio, and I is unit matrix, and H is the channel estimated in step 2, F _ifor 2 of employing ^li-th code book in codebook set;

Step 3-2, from capacity corresponding to each code book, select maximum code book, this maximum code book is the code book of the optimum in this moment code book;

Step 3-3, the optimum code book that step 3-2 obtains is carried out channel capacity with the optimum code book that previous moment is selected compare, code book maximum for capacity is sent code book as this moment; If previous moment is without code book, then the code book of current time is sent code book as this moment.

Step 4, transmitting terminal utilize the code book sequence number of the optimum of step 3 gained, find corresponding code book, and utilize this code book to carry out preliminary treatment to transmission data, pretreated data are sent afterwards.

Carry out preliminary treatment to transmission data, formula used is:

X＝F·D,

Wherein F is the optimum code book choosing out in step 3, and D is the data sent, and X is the data after precoding.

Be described in more detail below:

Composition graphs 1, the uplink precoding method based on rotation code book of a kind of fixing power communication terminal of the present invention, comprises the following steps:

Step 1, create that K different but the size of equivalence is 2 at transmitting terminal and receiving terminal simultaneously ^lcodebook set, and it is arranged, wherein K, L are natural number;

Each code book in codebook set is used alternatingly with same rule in transmission and receiving terminal.Usually, the code book used in the t=kT+nKT moment is by predetermined sequence k=ρ (t), and 0≤ρ (t)≤K-1 determines, this sequence is known for transmission and receiving terminal.Namely the code book used when feeding back moment t is in the present invention, codebook set is used alternatingly in an orderly manner, when feeding back moment t=(k+nK) T, and ρ (t)=(k+nK) mod K=k mod K, namely

$...,F_0^L,F_1^L,F_2^L,...,F_{K-1}^L,F_0^L,F_1^L,F_2^L,....$

Wherein for the code book corresponding to moment t=kT+nKT, and k=0,1,2, K-1, n are natural number, and T is the feedback interval of precoding.Such as, K and L can be chosen for natural number, K preferably 64, L preferably 4 in the present invention.

When not increasing number of bits of feedback, along with temporal extension, the mechanism of this rotation code book makes to send has more chance to use more pre-coding matrix with receiving terminal.This strategy is that transmission and receiving terminal provide a K virtual code book doubly, F ^{l+log K}.

Step 2, carry out channel estimating at receiving terminal according to descending pilot signal;

Channel status instruction reference signal (CSI-RS) that transmitting terminal can be utilized in the present invention to emit is estimated channel, and adopt the de-scrambling method of conjugate multiplication, formula is:

H＝Y _R·R ^*

Wherein, Y _rfor the CSI-RS received, R is the CSI-RS of transmitting terminal.

Step 3, utilize channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set, and this optimum code book sequence number is sent to transmitting terminal;

Receiving terminal utilizes channel status from 2 ^lfilter out optimum code book in individual codebook set specifically to comprise the following steps:

Step 3-1, determine the capacity that corresponding to each code book, channel can reach, formula used is:

C(F _i)＝log det(I+γ(HF _i) ^*(HF _i))＝log det(I+γF _i ^*H ^*HF _i)

Wherein, γ is signal noise ratio, and I is unit matrix, and H is the channel estimated in step 2, F _ifor 2 of employing ^li-th code book in codebook set.

Step 3-2, from capacity corresponding to each code book, select maximum code book, this maximum code book is the code book of the optimum in this moment code book, and formula used is:

Wherein for the codebook set adopted during moment t.

Step 3-3, the optimum code book that step 3-2 obtains is carried out channel capacity with the optimum code book that previous moment is selected compare, code book maximum for capacity is sent code book as this moment; If previous moment is without code book, then the code book of current time is sent code book as this moment.

Composition graphs 2, in order to the optimum code book that current time can be allowed can to choose previous moment, needs to retain a code word sequence number in advance in the code book of current time as default sequence number, the optimum code book once discovery previous moment is also that this sequence number is just fed back to transmitting terminal by the optimum code book of current time; If the code book of previous moment is not the optimum code book of current time, so just the code book sequence number of current time is fed back to transmitting terminal.Wherein this default sequence number is determined by a receiving terminal and all pre-specified random sequence of transmitting terminal.

Step 4, transmitting terminal utilize the code book sequence number of the optimum of step 3 gained, find corresponding code book, and utilize this code book to carry out preliminary treatment to transmission data, pretreated data are sent afterwards.

Transmitting terminal is according to the code book sequence number of feedback in step 3, and the code book finding this sequence number corresponding from the codebook set in corresponding moment, if the code book sequence number of feedback is default sequence number, so needs the optimum code book using previous moment.Utilize this code book to carry out preliminary treatment to transmission data afterwards, its formula is:

X＝F·D,

Wherein F is the optimum code book choosing out in step 3, and D is the data sent, and X is the data after precoding.

According to preferred parameter of the present invention, i.e. K preferably 64, L preferably 4, the tradition list codebook precoding performance of the performance that can reach and 8 bit feedback is suitable, that is the present invention can reach the performance of traditional 8 bit feedback by 4 bit feedback, has saved the expense of feedback bits; The gain of 3dB approximately additionally can be brought when same number of bits of feedback.

Claims (5)

1. the uplink precoding method based on rotation code book of fixing power communication terminal, is characterized in that, comprise the following steps:

Step 1, create that K different but the size of equivalence is 2 at transmitting terminal and receiving terminal simultaneously ^lcodebook set, and it is arranged, wherein K, L are natural number;

Step 2, carry out channel estimating at receiving terminal according to descending pilot signal;

Step 3, utilize channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set, and this optimum code book sequence number is fed back to transmitting terminal;

Step 4, transmitting terminal utilize the code book sequence number of the optimum of step 3 gained, find corresponding code book, and utilize this code book to carry out preliminary treatment to transmission data, pretreated data are sent afterwards.

2. fixing power communication terminal according to claim 1 based on rotating the uplink precoding method of code book, it is characterized in that, K the difference created in the step 1 but size of equivalence is 2 ^lcodebook set put in order into:

$...,F_0^L,F_1^L,F_2^L,...,F_{K-1}^L,F_0^L,F_1^L,F_2^L,...$

Wherein for the code book corresponding to moment t=kT+nKT, and k=0,1,2, K-1, n are natural number, and T is the feedback interval of precoding.

3. fixing power communication terminal according to claim 1 based on rotating the uplink precoding method of code book, it is characterized in that, in step 2 at receiving terminal according to the de-scrambling method specifically adopting conjugate multiplication when utilizing down-bound pilot frequency signal to carry out channel estimating.

4. the uplink precoding method based on rotation code book of fixing power communication terminal according to claim 1, it is characterized in that, step 3 utilizes channel status from 2 at receiving terminal ^lfilter out optimum code book in individual codebook set specifically to comprise the following steps:

Step 3-1, determine the capacity C (F that channel corresponding to each code book can reach _i), formula used is:

C(F _i)＝log det(I+γ(HF _i) ^*(HF _i))＝log det(I+γF _i ^*H ^*HF _i)

Wherein, γ is signal noise ratio, and I is unit matrix, and H is the channel estimated in step 2, F _ifor 2 of employing ^li-th code book in codebook set;

Step 3-2, from capacity corresponding to each code book, select maximum code book, this maximum code book is the code book of the optimum in this moment code book;

Step 3-3, the optimum code book that step 3-2 obtains is carried out channel capacity with the optimum code book that previous moment is selected compare, code book maximum for capacity is sent code book as this moment; If previous moment is without code book, then the code book of current time is sent code book as this moment.

5. the uplink precoding method based on rotation code book of fixing power communication terminal according to claim 1, is characterized in that, utilize the code book of the optimum of step 3 gained to carry out preliminary treatment to transmission data in step 4, formula used is:

X＝F·D,

Wherein F is the optimum code book choosing out in step 3, and D is the data sent, and X is the data after precoding.