CN104506275B - A kind of LTE signal transmission systems based on automatic adjusument reference vector - Google Patents

Abstract

An LTE signal transmission system based on an adaptive adjustment reference vector. The LTE signal transmission system based on the self-adaptive adjustment reference vector of the present invention solves the problem of mutual limitation of the transmission efficiency and the transmission bandwidth of the existing LTE system, and also better solves the influence of higher modulation gain on the transmission efficiency of the system problem, greatly improving the frequency band utilization. The system includes a transmitting unit, a receiving unit, and a coding vector offset relationship preset unit, wherein the transmitting unit includes a sequentially connected first multiplexing unit, a grouping unit, a joint transmitting signal generating unit, and a radio frequency transmitting unit, The receiving unit includes a correlator unit, a demultiplexing unit, and a second demultiplexing unit connected in sequence.

Description

A LTE Signal Transmission System Based on Adaptive Adjustment Reference Vector

technical field

The invention relates to the field of wireless communication, in particular to an LTE signal transmission system based on an adaptive adjustment reference vector.

Background technique

LTE (Long Term Evolution) is a long-term evolution of the UMTS (Universal Mobile Telecommunications System) technical standard formulated by 3GPP (Third Generation Partnership Project). It was officially established and launched at the 3GPP Toronto TSGRAN#26 meeting in December 2004. The LTE system introduces key transmission technologies such as OFDM (Orthogonal Frequency Division Multiplexing) and MIMO (Multiple Input Multiple Output), which significantly increases the spectral efficiency and data transmission rate (20M bandwidth 2X2MIMO in the case of 64QAM, the theoretical maximum transmission rate of the downlink is 201Mbps, about 140Mbps after excluding signaling overhead, but according to actual networking and terminal capability limitations, it is generally believed that the peak rate of downlink is 100Mbps, and the peak rate of uplink is 50Mbps), and supports multiple bandwidth allocations: 1.4MHz, 3MHz, 5MHz, 10MHz, 15MHz and 20MHz, etc., and supports global mainstream 2G/3G frequency bands and some new frequency bands, so the spectrum allocation is more flexible, and the system capacity and coverage are also significantly improved. The LTE system network architecture is flatter and simpler, reducing network nodes and system complexity, thereby reducing system delay and network deployment and maintenance costs. The LTE system supports interoperability with other 3GPP systems. There are two types of LTE systems: FDD-LTE and TDD-LTE, that is, frequency division duplex LTE system and time division duplex LTE system. The main difference between the two technologies lies in the physical layer of the air interface (such as frame structure, time division design, synchronization, etc.). FDD-LTE system air interface uplink and downlink transmission uses a pair of symmetrical frequency bands to receive and transmit data, while TDD-LTE system uses the same frequency band for uplink and downlink transmission in different time slots. Compared with FDD duplex mode, TDD has a higher spectrum utilization.

However, in the existing LTE system, its signal transmission is still limited by the frequency band bandwidth, but it has very high requirements on the data transmission rate. The data transmission efficiency is still the focus of research.

Contents of the invention

The purpose of the present invention is achieved through the following technical solutions.

According to an embodiment of the present invention, an LTE signal transmission system based on an adaptive adjustment reference vector is proposed, the system includes a transmitting unit, a receiving unit, and a coding vector offset relationship preset unit, wherein the transmitting unit includes sequentially connected The first multiplexing unit, the grouping unit, the joint transmitting signal generating unit, and the radio frequency transmitting unit, the receiving unit includes a correlator unit, a multiplexing recovery unit, and a second multiplexing unit connected in sequence.

According to an embodiment of the present invention, the encoding vector offset relationship preset unit presets the encoding vector offset relationship; specifically includes:

The transmitting unit and the receiving unit pre-set the same M-dimensional pseudo-noise coding vector offset relationship, and define the combination form of the M-dimensional pseudo-noise coding vector as follows:

L is the number of coding elements in each pseudo-noise coding cycle, and the vector with the smallest identification number among the r vectors is selected as the adaptive adjustment reference vector. A total of r vectors, the identification number NO ₁ <NO ₂ <...<NO _r , PN _i (0) is the i-th (i=NO ₂ , NO ₃ ,...,NO _r ) vector relative to the M vectors at the 0th position of the fixed reference vector, the

The position of the i-th vector shifted to the left relative to the position of the self-adaptive adjustment reference vector is defined as PN _i (p):

According to an embodiment of the present invention, the first multiplexing unit performs multiplexing on the data to be transmitted to obtain a Q-channel signal; specifically, it includes:

During the transmission process, the transmitted Q-bit data is recorded as d ₁ , d ₂ , d ₃ ,..., d _Q , and each information data cycle is T _d , where QT _d = LT _c , and L is the number of times of each pseudo-noise coding cycle The number of coding elements, T _c is the chip period; the Q-bit transmission information is sent to the multiplexer to obtain the Q-channel signal.

According to an embodiment of the present invention, the grouping unit specifically includes:

The obtained Q-channel signal is divided into three groups according to the corresponding relationship between the signal vector offset state and the data, and the three groups correspond to bit, r bit, and (r-1) [log ₂ L] bit; wherein, the vector offset state includes:

State 1: According to the data matching algorithm, r transmitted vectors are selected from the pseudo-noise vector family composed of M pseudo-noise encoding vectors, and there are a total of Screening of a transmission modulation vector, corresponding to the transmission Bit information data, [x] represents the integer part of x, is the combination of taking r from M;

State 2: The selected r modulation vectors only use the positive phase or negative phase state. If a certain phase state of the r modulation vectors is selected for transmission, there are 2 ^r phase states for transmission, corresponding to the information data that can transmit r bits ;

State 3: Among the selected r vectors, the vector with the smallest vector identification number is used as the current reference vector, and among the other (r-1) vectors, each vector has L positions that can be screened for emission, and there are ( r-1) [log ₂ L] bit information transmission;

Corresponding the above vector offset state with the data to be transmitted one by one, the corresponding information data Q is:

According to an embodiment of the present invention, the joint transmission signal generating unit generating the joint transmission signal specifically includes: combining the selected r transmission pseudo-noise coding vectors and vector offset states together for transmission to form an adaptive adjustment reference vector Combination relationship of modulation signal offset:

In the formula, The r vectors are combined in multiple ways to form a joint transmission signal:

MD is the joint emission signal, t is the time variable, The i-th emission vector is shifted to the left relative to the fixed reference vector for the j-th time locations.

According to an embodiment of the present invention, the radio frequency transmitting unit performs radio frequency conversion on the joint transmission signal before transmitting, and the transmission signal is s(t):

In the formula, P is the RF transmit power.

According to an embodiment of the present invention, the correlator unit is used to receive and demodulate received signals, specifically including:

Under the random hash noise channel, the above-mentioned transmitted signal is received, and the received signal is

r(t)=s(t-τ)+n(t)+J(t),

In the formula, τ is communication propagation delay; n(t) is random hash noise, J(t) is interference signal;

The M correlators set by the receiving unit are respectively used for demodulation processing with PN _i (t) (i=1, 2,...M) after radio frequency transmission demodulation, then the i-th (1≤i) of the M correlators ≤M) correlator outputs are:

In the formula, τ is the communication propagation delay; the integral of i=i _j is the autocorrelation of the modulation vector; i≠ij is the cross-correlation; the output of the correlator is

The two sets of pseudo-noise vectors used are quasi-orthogonal to each other.

According to an embodiment of the present invention, the multiplex recovery unit is used to recover Q-channel data information from the demodulated signal; specifically includes:

Perform data-vector screening and inverse matching on the obtained M correlator output values and their corresponding pseudo-noise code identification numbers, and select the r output values corresponding to the largest absolute value from the L phase output values of the M correlators. The modulation vector identification number and the offset relationship are used as the joint transmission vector to be transmitted. Among them, the one with the smallest vector identification number is the current reference vector, and the offset positions of other large identification numbers are based on the current reference vector. Data- Offset reverse matching to obtain the received Q-channel data information;

According to an embodiment of the present invention, the second multiplexing unit converts the received Q-channel data information into single-channel to obtain Q-bit information.

According to an embodiment of the present invention, the selection of r transmitted vectors from the pseudo-noise vector family composed of M pseudo-noise encoding vectors according to the data matching algorithm is specifically:

A1. Record the transmitted Q-bit data as d ₁ , d ₂ , d ₃ ,..., d _Q , and divide them into three parts, as

d ₁ , d ₂ , d ₃ , . . . , d _k = {d _{s} , d _{e} , d _{p} };

where d _{s} is

where d _{e} is

where d _{p} is

In the formula, k3=(r-1)[log ₂ L];

A2. Taking d _{s} as r-bit information, binary 0 can be defined as positive phase, binary 1 is negative phase, the first The data corresponds to the selected first vector phase, the first The data corresponds to the selected rth vector phase, there are 2 ^r possible states, and the corresponding information data is r bits;

A3. Select r vectors from M vectors, and follow the same matching principle as conventional parallel joint modulation sorting, there is possible states, the corresponding information data is bit;

A4. Divide d _{p} bit information into (r-1) groups, each group is p _i bits, and according to pi bits, offset the i-th vector of the reference vector for adaptive adjustment The state is vector shifted, with possible states, the corresponding information data is (r-1)·[log ₂ L] bits.

The advantage of the present invention is that: the present invention solves the problem of mutual limitation of transmission efficiency and transmission bandwidth of the existing LTE system, and also better solves the problem of the influence of higher modulation gain on system transmission efficiency, and greatly improves the frequency band utilization rate.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating a preferred embodiment and are not to be considered as limiting the invention. Also throughout the drawings, the same reference numerals are used to designate the same components. In the attached picture:

Fig. 1 shows an LTE signal transmission system based on an adaptively adjusted reference vector according to an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

According to an embodiment of the present invention, an LTE signal transmission system based on an adaptive adjustment reference vector is proposed. As shown in FIG. 1 , the system includes a transmitting unit, a receiving unit, and a coding vector offset relationship preset unit, wherein, The transmitting unit includes a sequentially connected first multiplexing unit, a grouping unit, a joint transmitting signal generating unit, and a radio frequency transmitting unit, and the receiving unit includes a sequentially connected correlator unit, a multiplexing recovery unit, and a second multiplexing unit. road transformation unit.

According to an embodiment of the present invention, the encoding vector offset relationship preset unit presets the encoding vector offset relationship; specifically includes:

The transmitting unit and the receiving unit pre-set the same M-dimensional pseudo-noise coding vector offset relationship, and define the combination form of the M-dimensional pseudo-noise coding vector as follows:

L is the number of coding elements in each pseudo-noise coding cycle, and the vector with the smallest identification number among the r vectors is selected as the reference vector, that is, the reference vector is adaptively adjusted. There are r vectors in total, the identification number NO ₁ <NO ₂ <...<NO _r , the vector is the self-adaptive adjustment reference vector for this information transmission, PN _i (0) is the i-th among the M vectors (i=NO ₂ , NO ₃ ,..., NO _r ) vectors relative to the 0th position of the fixed reference vector, the

The position of the i-th vector shifted to the left relative to the position of the self-adaptive adjustment reference vector is defined as PN _i (p):

According to an embodiment of the present invention, the first multiplexing unit performs multiplexing on the data to be transmitted to obtain a Q-channel signal; specifically, it includes:

During the transmission process, the transmitted Q-bit data is recorded as d ₁ , d ₂ , d ₃ , ..., d _Q , and each information data cycle is T _d , where QT _d = LT _c , and L is the time period of each pseudo-noise coding cycle The number of coding elements, T _c is the chip period; the Q-bit transmission information is sent to the multiplexer to obtain the Q-channel signal.

According to an embodiment of the present invention, the grouping unit specifically includes:

The obtained Q-channel signal is divided into three groups according to the corresponding relationship between the signal vector offset state and the data, and the three groups correspond to bit, r bit, and (r-1) [log ₂ L] bit; wherein, the vector offset state includes:

State 1: According to the data matching algorithm, r transmitted vectors are selected from the pseudo-noise vector family composed of M pseudo-noise encoding vectors, and there are a total of Screening of a transmission modulation vector, corresponding to the transmission Bit information data, [x] represents the integer part of x, is the combination of taking r from M;

State 2: The selected r modulation vectors only use the positive phase or negative phase state. If a certain phase state of the r modulation vectors is selected for transmission, there are 2 ^r phase states for transmission, corresponding to the information data that can transmit r bits ;

State 3: Among the selected r vectors, the vector with the smallest vector identification number is used as the current reference vector, and among the other (r-1) vectors, each vector has L positions that can be screened for emission, then there are ( r-1) [log ₂ L] bit information transmission;

Corresponding the above vector offset state with the data to be transmitted one by one, the corresponding information data Q is:

According to an embodiment of the present invention, the joint transmission signal generating unit generating the joint transmission signal specifically includes: combining the selected r transmission pseudo-noise coding vectors and vector offset states together for transmission to form an adaptive adjustment reference vector Combination relationship of modulation signal offset:

In the formula, The r vectors are combined in multiple ways to form a joint transmission signal:

MD is the joint emission signal, t is the time variable, The i-th emission vector is shifted to the left relative to the fixed reference vector for the j-th time locations.

According to an embodiment of the present invention, the radio frequency transmitting unit performs radio frequency conversion on the joint transmission signal before transmitting, and the transmission signal is s(t):

In the formula, P is the RF transmit power.

According to an embodiment of the present invention, the correlator unit is used to receive and demodulate received signals, specifically including:

Under the random hash noise channel, the above-mentioned transmitted signal is received, and the received signal is

r(t)=s(t-τ)+n(t)+J(t),

In the formula, τ is the communication propagation delay; n(t) is the random hash noise, and its double sideband power spectral density is N ₀ /2; J(t) is the interference signal; The phase is completely synchronized;

The M correlators set by the receiving unit are respectively used for demodulation processing with PN _i (t) (i=1, 2,...M) after radio frequency transmission demodulation, then the i-th (1≤i) of the M correlators ≤M) correlator outputs are:

In the formula, τ is the communication propagation delay; the integral of i=i _j is the autocorrelation of the modulation vector; i≠ij is the cross-correlation; the output of the correlator is

The two sets of pseudo-noise vectors used are quasi-orthogonal to each other.

According to an embodiment of the present invention, the multiplex recovery unit is used to recover Q-channel data information from the demodulated signal; specifically includes:

Perform data-vector screening and inverse matching on the obtained M correlator output values and their corresponding pseudo-noise code identification numbers, and select the r output values corresponding to the largest absolute value from the L phase output values of the M correlators. The modulation vector identification number and the offset relationship are used as the joint transmission vector to be transmitted. Among them, the one with the smallest vector identification number is the current reference vector, and the offset positions of other large identification numbers are based on the current reference vector. Data- Offset reverse matching to obtain the received Q-channel data information;

According to an embodiment of the present invention, the second multiplexing unit converts the received Q-channel data information into single-channel to obtain Q-bit information.

According to an embodiment of the present invention, the selection of r transmitted vectors from the pseudo-noise vector family composed of M pseudo-noise encoding vectors according to the data matching algorithm is specifically:

A1. Record the transmitted Q-bit data as d ₁ , d ₂ , d ₃ ,..., d _Q , and divide them into three parts, as

d ₁ , d ₂ , d ₃ , . . . , d _k = {d _{s} , d _{e} , d _{p} };

where d _{s} is

where d _{e} is

where d _{p} is

In the formula, k3=(r-1)[log ₂ L];

A2. Taking d _{s} as r-bit information, binary 0 can be defined as positive phase, binary 1 is negative phase, the first The data corresponds to the selected first vector phase, the first The data corresponds to the selected rth vector phase, there are 2 ^r possible states, and the corresponding information data is r bits;

A3. Select r vectors from M vectors, and follow the same matching principle as conventional parallel joint modulation sorting, there is possible states, the corresponding information data is bit;

A4. Divide d _{p} bit information into (r-1) groups, each group is p _i bits, and according to pi bits, offset the i-th vector of the reference vector for adaptive adjustment The state is vector shifted, with possible states, the corresponding information data is (r-1)·[log ₂ L] bits.

According to the embodiment of the present invention, the reference vectors of each transmitted data are different, and the one with the smallest vector identification number is used as the current reference vector, and the offset positions of other large identification numbers are all offset based on the current reference vector modulation. The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (4)

1. A LTE signal transmission system based on an adaptive adjustment reference vector, said system comprising a transmitting unit, a receiving unit and a coding vector offset relation preset unit, wherein said transmitting unit comprises a sequentially connected first multiplexing unit, a grouping unit, a joint transmission signal generation unit, and a radio frequency transmission unit, the receiving unit includes a correlator unit, a multiplexing recovery unit, and a second multiplexing conversion unit connected in sequence; The encoding vector offset relationship preset unit presets the encoding vector offset relationship; specifically includes: The transmitting unit and the receiving unit pre-set the same M-dimensional pseudo-noise coding vector offset relationship, and define the combination form of the M-dimensional pseudo-noise coding vector as follows: L is the number of coding elements in each pseudo-noise coding cycle, select the vector with the smallest identification number among the r vectors as the adaptive adjustment reference vector, and select A total of r vectors, the identification number NO ₁ <NO ₂ <...<NO _r , PN _i (0) is the i-th of the M vectors, i=NO ₂ , NO ₃ ,..., NO _r , the vectors are relative In the 0th position of the adaptive adjustment reference vector, the The position of the i-th vector shifted to the left relative to the position of the self-adaptive adjustment reference vector is defined as PN _i (p): The first multiplexing unit performs multiplexing on the data to be transmitted to obtain a Q-channel signal; specifically including: During the transmission process, the transmitted Q-bit data is recorded as d ₁ , d ₂ , d ₃ ,..., d _Q , and each information data cycle is T _d , where QT _d = LT _c , and L is the number of times of each pseudo-noise coding cycle The number of coding elements, T _c is the chip period; the Q bit transmission information is sent to the multiplexer to obtain the Q channel signal; The grouping unit grouping the Q channel signals specifically includes: The obtained Q-channel signal is divided into three groups according to the corresponding relationship between the signal vector offset state and the data, and the three groups correspond to bit, r bit, and (r-1) [log ₂ L] bit; wherein, the vector offset state includes: State 1: According to the data matching algorithm, r transmitted vectors are selected from the pseudo-noise vector family composed of M pseudo-noise encoding vectors, and there are a total of Screening of a transmission modulation vector, corresponding to the transmission Bit information data, [x] represents the integer part of x, is the combination of taking r from M; State 2: The selected r modulation vectors only use the positive phase or negative phase state. If a certain phase state of the r modulation vectors is selected for transmission, there are 2 ^r phase states for transmission, corresponding to the information data that can transmit r bits ; State 3: Among the selected r vectors, the vector with the smallest vector identification number is used as the current reference vector. Among the other r-1 vectors, each vector has L positions that can be screened for launch, and there are (r- 1) [log ₂ L] bit information transmission; Corresponding the above vector offset state with the data to be transmitted one by one, the corresponding information data is: 2. A system as claimed in claim 1, said multiplex restoration unit is used to restore Q path data information from the demodulated signal; specifically comprising: Perform data-vector screening and inverse matching on the obtained M correlator output values and their corresponding pseudo-noise code identification numbers, and select the r output values corresponding to the largest absolute value from the L phase output values of the M correlators. The modulation vector identification number and the offset relationship are used as the joint transmission vector to be transmitted. Among them, the one with the smallest vector identification number is the current reference vector, and the offset positions of other large identification numbers are based on the current reference vector. Data- The offset inverse matching is used to obtain the received Q-channel data information. 3. A system according to claim 2, wherein said second multiplexing unit converts the received Q-channel data information into single-channel conversion to obtain Q-bit information. 4. a kind of system as claimed in claim 3, described according to data matching algorithm selects the vector of r transmission from the pseudo-noise vector family that M pseudo-noise encoding vectors form is specifically: A1. Record the transmitted Q-bit data as d ₁ , d ₂ , d ₃ ,..., d _Q , and divide them into three parts, as d ₁ , d ₂ , d ₃ , . . . , d _k = {d _{s} , d _{e} , d _{p} }; where d _{s} is where d _{e} is In the formula, where d _{p} is In the formula, k3=(r-1)[log ₂ L]; A2, d _{s} is the r-bit information, define binary 0 as positive phase, binary 1 as negative phase, the first The data corresponds to the selected first vector phase, the first The data corresponds to the selected rth vector phase, there are 2 ^r possible states, and the corresponding information data is r bits; A3. Select r vectors from M vectors, and follow the same matching principle as conventional parallel joint modulation sorting, there is possible states, the corresponding information data is bit; A4. Divide d _{p} bits of information into r-1 groups, each group is p _i bits, and according to p _i bits, offset the i-th vector of the reference vector for adaptive adjustment The state is vector shifted, with possible states, the corresponding information data is (r-1)·[log ₂ L] bits.