CN104468053B - A kind of multi-antenna multiplexed Transmission system based on NGB W - Google Patents

Abstract

The present invention provides a multi-antenna multiplexing transmission system based on NGB-W, which includes a sending device and a receiving device. The sending device includes: a dual-antenna mapping module, a precoding processing module, a time interleaving module, a framing module, and a frequency domain Interleaving module and OFDM symbol generation module; the receiving device includes: OFDM demodulation module, channel estimation module, multi-antenna channel matrix processing module, frequency domain deinterleaving module, frame extraction module, time deinterleaving module, multi-antenna demodulation module , A multi-antenna demapping module. The present invention precodes the transmitted signal of the NGB-W system, including constant precoding matrix and phase jump matrix processing, which can improve the performance gain under the relevant channel transmission of the broadcasting system, and solve the problem of NGB-W system broadcasting in the prior art. The problem of not being able to get a higher transfer rate.

Description

A Multi-antenna Multiplexing Transmission System Based on NGB-W

technical field

The present invention relates to the technical field of mobile communications, in particular to the technical field of multi-antenna transmission methods in the field of mobile communications, and specifically to an NGB-W-based multi-antenna multiplexing transmission system.

Background technique

With the rapid development of world economy and culture, the demand of mobile users for information services is increasing rapidly. Relying solely on the traditional broadcasting network or the traditional two-way communication network, it is impossible to realize the optimal transmission of mobile information services. The next-generation radio and television network wireless (NGB-W) communication system can realize the fusion and coexistence of wireless broadcasting and two-way communication, and is an effective way to solve the contradiction between the rapid growth of mobile information service data volume and the limited transmission capacity of wireless networks. The NGB-W system will take into account both terrestrial broadcasting (both mobile reception and fixed reception) and mobile broadcasting (which can be the existing CMMB service or future NGB-W service). In order to improve the transmission rate of the NGB-W system, NGB-W introduces multiple antenna multiplexing transmission technology. For roof-top fixed reception scenarios and mobile reception scenarios for handheld devices, due to the characteristics of the broadcast channel, there is a strong direct path, so there is a strong channel correlation. Moreover, due to the one-way transmission characteristics of the broadcasting system, the multi-antenna technology based on channel feedback generally adopted in the mobile communication system will not be applicable. At present, the research on multi-antenna transmission performance and key technologies in the broadcast channel scenario is not perfect, and there is no actual system that can be applied.

Most of the existing broadcast communication standards do not adopt multi-antenna transmission technology. For example, the well-known DVB-T2 system in Europe only adopts the space diversity technology of two antennas of the transmitting device. At present, the 2-antenna space multiplexing technology is only used in the draft of the DVB-NGH standard that has just been released, and the high-order modulation optimization scheme of 2-stream 64QAM is not supported, and a higher transmission rate cannot be obtained.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a multi-antenna multiplexing transmission system based on NGB-W, which is used to solve the problem that the NGB-W system broadcast cannot obtain a higher transmission rate in the prior art. question.

In order to achieve the above object and other related objects, the present invention provides a multi-antenna multiplexing transmission system based on NGB-W, including a sending device and a receiving device, and the sending device includes: a dual-antenna mapping module, which is used to convert the modulated The serial symbol data sequence is mapped to the symbol data sequence transmitted on two parallel antennas; the precoding processing module is connected to the output of the dual-antenna mapping module, and is used to perform precoding matrix processing on the input symbol data sequence; time interleaving The module is connected to the output end of the precoding processing module, and is used to complete the interleaving operation of the symbol data sequence in time; the framing module is connected to the output end of the time interleaving module, and is used to frame the interleaved symbol data sequence Processing; the frequency domain interleaving module is connected to the output end of the framing module, and is used for interleaving processing of the symbol data sequence on the frequency domain subcarrier; the OFDM symbol generation module is connected to the output end of the frequency domain interleaving module, and the symbol data sequence is Complete the pilot addition, IFFT transformation, and cyclic prefix addition operations, and send through the radio frequency units of the two antennas; the receiving device includes: an OFDM demodulation module, connected to the receiving antenna, used to send the data sent by the sending device The baseband signal is subjected to OFDM demodulation processing; the channel estimation module is connected to the output of the OFDM demodulation module to complete the estimation of the multi-antenna channel fading coefficient of the received signal; the multi-antenna channel matrix processing module is connected to the output of the channel estimation module Terminals are connected to process the estimated multi-antenna spatial channel values to facilitate correct antenna demodulation of data; the frequency domain deinterleaving module is connected to the output of the OFDM demodulation module for receiving symbol data in the frequency domain Deinterleaving processing on the subcarrier; frame extraction module, connected to the output of the frequency domain deinterleaving module, used to perform frame extraction processing on the symbol data sequence after frequency domain deinterleaving; time deinterleaving module, connected with the frame extraction module The output terminals are connected to complete the deinterleaving operation of the symbol data sequence in time; the multi-antenna demodulation module is connected to the output terminals of the time deinterleaving module and the multi-antenna channel matrix processing module, and uses the estimated channel fading coefficient to The sampling signal is subjected to frequency domain equalization; the multi-antenna demapping module is connected to the output end of the multi-antenna demodulation module, and is used to transform the parallel symbol data sequence on the input two antennas into a serial output symbol data sequence.

Preferably, if the modulated serial symbol data sequence is expressed as Then the output symbolic data sequence can be expressed in vector form as Among them, N _{Cells, FEC_block} is the number of data units in each FEC block.

Preferably, in the precoding processing module, the output symbol data sequence z _k is multiplied by the precoding matrix w(k), and the output vector can be expressed as

in:

w(k)=D(k)U, k=0,1,...,N _{Cells, FEC_block} /2-1;

D(k) is a phase jump matrix with a period of 8,

U is a constant precoding matrix, a is a constant.

Preferably, in the OFDM demodulation module, the OFDM demodulation process includes at least cyclic prefix removal and FFT transformation operations.

Preferably, in the multi-antenna channel matrix processing module, processing the estimated multi-antenna spatial channel values includes frequency domain deinterleaving, frame extraction and time deinterleaving.

As mentioned above, an NGB-W-based multi-antenna multiplexing transmission system of the present invention has the following beneficial effects:

1. The present invention proposes a multi-antenna multiplexing transmission system based on NGB-W multi-antenna multiplexing transmission technology including a transmitting device and a receiving device. By precoding the transmitted signal of the NGB-W system, it includes a constant precoding matrix and The phase jump matrix processing can improve the performance gain under the relevant channel transmission of the broadcast system, obtain space multiplexing and space diversity gain, and can solve the problem that the NGB-W system broadcast cannot obtain a higher transmission rate in the prior art.

2. The values in the precoding matrix processing structure proposed by the present invention are specifically optimized for the NGB-W system, including two-stream transmission scenarios of QPSK, 16QAM and 64QAM, and the optimal bit error rate performance can be obtained.

3. The present invention proposes a multi-antenna demodulation structure of a receiving device based on NGB-W system transmission signals, thereby accurately obtaining the frequency-domain spatial channel matrix corresponding to the expected data symbol, completing frequency-domain equalization, and improving system performance.

Description of drawings

FIG. 1 is a schematic structural diagram of a sending device in an NGB-W-based multi-antenna multiplexing transmission system according to the present invention.

FIG. 2 is a schematic structural diagram of a receiving device in an NGB-W-based multi-antenna multiplexing transmission system according to the present invention.

FIG. 3 is a performance curve diagram of bit error rate and a value under different signal-to-noise ratio conditions in an NGB-W-based multi-antenna multiplexing transmission system of the present invention.

FIG. 4 shows a performance comparison diagram of SM system bit error rate optimized for a traditional SM and an NGB-W-based multi-antenna multiplexing transmission system based on the present invention.

Component designation description

1 sender

11 Dual Antenna Mapping Module

12 Precoding processing module

13 Time interleaving module

14 framing modules

15 Frequency domain interleaving module

16 OFDM symbol generation module

2 receiving device

21 OFDM demodulation module

22 channel estimation module

23 Multi-antenna channel matrix processing module

24 frequency domain deinterleaving module

25 frame extraction module

26 time deinterleaving module

27 Multi-antenna demodulation module

28 multi-antenna demapping module

detailed description

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

The purpose of the present invention is to provide a multi-antenna multiplex transmission system based on NGB-W, which is used to solve the problem in the prior art that NGB-W system broadcast cannot obtain a higher transmission rate. The principle and implementation of an NGB-W-based multi-antenna multiplexing transmission system of the present invention will be described in detail below, so that those skilled in the art can understand the NGB-W-based multi-antenna of the present invention without creative work multiplexing transmission system.

The present invention is proposed for the NGB-W multi-antenna system: First, the inventive system should take advantage of the multiplexing and diversity advantages of the multi-antenna system, thereby adopting a precoding matrix processing structure, and performing coding matrix value targeting at specific broadcast-related channel scenarios Preferably; second, due to the time, frequency domain interleaving processing of the NGB-W system transmitting device and the multi-antenna phase rotation processing structure related to the symbol data index, the multi-antenna detection of the receiving device needs to adopt an equivalent special processing method, thereby more Effectively perform MIMO equalization to improve system performance.

The present invention provides an NGB-W-based multi-antenna multiplexing transmission system, including a sending device and a receiving device. According to the characteristics of NGB-W broadcast channel, the precoding processing method is used to improve the system performance gain of channel correlation, and according to the processing characteristics of the transmitting device, a multi-antenna demodulation structure of the receiving device based on the NGB-W system transmission signal is proposed, so as to accurately The frequency domain spatial channel matrix corresponding to the expected symbol of the data is obtained accurately, and the frequency domain equalization is completed, which improves the system performance. The sending device and the receiving device will be described in detail below respectively.

A. Sending device

As shown in FIG. 1 , the sending device 1 is composed of a dual-antenna mapping module 11 , a precoding processing module 12 , a time interleaving module 13 , a framing module 14 , a frequency domain interleaving module 15 and an OFDM symbol generation module 16 connected in sequence.

If the modulated serial symbol data sequence is expressed as

Wherein, N _{Cells, FEC_block} is the number of data units in each FEC block.

First, the output end of the dual-antenna mapping module 11 is connected to the precoding processing module 12, and is used to map the modulated serial symbol data sequence to the symbol data sequence transmitted on the two parallel antennas, then the output modulation symbol pair is represented by In vector form it can be expressed as

The precoding processing module 12 is connected to the output end of the dual-antenna mapping module 11, and is used to perform precoding matrix processing on the input symbol data. On the one hand, it can improve the dual-antenna multiplexing transmission performance under the broadcast-related channel, and on the other hand, through Phase jump to further obtain space diversity gain, the specific encoding scheme is as follows:

The precoding processing module 12 multiplies the modulation symbol pair z _k with the precoding matrix w(k), and the output vector can be expressed as:

Wherein the precoding processing module 12 is formed by multiplying two parts of the constant precoding matrix and the phase jump matrix, namely

w(k)=D(k)U, k=0,1,...,N _{Cells, FEC_block} /2-1;

Among them, the constant precoding matrix is to process the modulation symbol pairs on the two antennas, expressed as:

a is a constant.

Here, we optimize the value of parameter a in this orthogonal matrix to minimize the bit error rate performance of the NGB-W system. The optimized values are applied to 4, 8, and 12 bits/virtual resource element (bpcu) scenarios respectively, that is, the modulation modes of the constellation symbols transmitted on the two antennas are the same, which are QPSK, 16QAM, and 64QAM respectively. The specific value of parameter a is given in the following specific examples.

In addition, for the phase jump matrix operation in the precoding process, the periodic jump of the symbol data phase on antenna 2 is actually completed, and the matrix D(k) can be expressed as:

Among them, D(k) is a phase jump matrix with a period of 8, and this optimized value is also given after specific optimization for the NGB-W system. On the one hand, because in the NGB-W system, no matter what modulation method is used, N _{Cells, FEC_block} /2 is always divisible by 8, so the modulation symbol pairs generated by the same coding block always contain an integer number of phase jumps cycle. On the other hand, the phase jump mode with a period of 8 can already ensure that the NGB-W system can obtain the maximum space diversity gain. Therefore, for each coding block, the starting symbol phase is 0, and gradually increases with a step size of 2π/8, that is, the jump type changes with a period of 8 modulation symbol pairs, and has nothing to do with the system modulation mode.

The time interleaving module 13 is connected to the output terminal of the precoding processing module 12, and is used to complete the time interleaving operation of the symbol data.

The framing module 14 is connected to the output end of the time interleaving module, and is used for framing the interleaved symbol data.

The frequency-domain interleaving module 15 is connected to the output end of the framing module 14, and is used for interleaving the symbol data on the frequency-domain subcarriers.

The OFDM symbol generation module 16 is connected to the output terminal of the frequency domain interleaving module 15 to complete operations such as pilot addition, IFFT transformation, and cyclic prefix addition, and finally transmit through the radio frequency units of the two antennas.

B. Receiver

As shown in Figure 2, the receiving device 2 consists of an OFDM demodulation module 21, a channel estimation module 22, a multi-antenna channel matrix processing module 23, a frequency domain deinterleaving module 24, a frame extraction module 25, a time deinterleaving module 26, multiple The antenna demodulation module 27 and the multi-antenna demapping module 28 are composed, and the connection sequence is shown in FIG. 2 .

The OFDM demodulation module 21 is connected to the receiving antenna, and is used for performing OFDM demodulation processing on the received baseband signal in the wireless channel, including operations such as removing cyclic prefix and FFT transformation.

The channel estimation module 22 is connected to the output terminal of the OFDM demodulation module 21, and is used for estimating the multi-antenna channel fading coefficient of the received signal.

The multi-antenna channel matrix processing module 23 is connected to the output of the channel estimation module 22, and is used to process the estimated 4-way multi-antenna spatial channel values similar to the data, including frequency domain deinterleaving, frame extraction and time deinterleaving Module 26, to facilitate multi-correct antenna demodulation of data.

The frequency domain deinterleaving module 24 is connected to the output terminal of the OFDM demodulation module 21, and is used for deinterleaving processing of received symbol data on frequency domain subcarriers.

The frame extraction module 25 is connected to the output terminal of the frequency domain deinterleaving module 24, and is used for performing frame extraction processing on the symbol data after frequency domain deinterleaving.

The time deinterleaving module 26 is connected to the output terminal of the frame extracting module 25, and is used to complete the deinterleaving operation of symbol data in time.

The multi-antenna demodulation module 27 is connected to the output terminals of the time deinterleaving module 26 and the multi-antenna channel matrix processing module 23, and uses the estimated channel fading coefficient to perform frequency domain equalization on the sampled signal.

The multi-antenna demapping module 28 is connected to the output end of the multi-antenna demodulation module 27, and is used for converting the input parallel data sequence on the two antennas into a serial output data sequence. This recovers the serial symbols at the original constellation points.

The demodulation principle of the receiving device 2 will be described in detail below, and the difference between the processing method of the receiving device 2 of the present invention and the traditional multi-antenna demodulation of OFDM signals will be explained.

Assuming a 2*2 multi-antenna channel at the transmitting end, after precoding matrix processing, the transmitted signals of the two antennas are expressed as follows:

In the following data expressions of the sending end and receiving end, lowercase letters represent antenna 1, and uppercase letters represent antenna 2.

Assume that the two streams of data after precoding processing are: Wherein X _i =[x _0,i x _1,i ... x _N-1,i ], i=0,1, N=N _{Cells, FEC_block} /2.

After the sending device 1 undergoes interleaving processing and generates OFDM symbols, that is, IFFT transformation, and then passes through the MIMO channel, and then performs OFDM demodulation, the equivalent in the frequency domain is as follows:

in

The frequency-domain and time-domain interleaving processing operations can be uniformly expressed as an interleaving matrix B, and it is satisfied that the matrix B is a unitary matrix of order N×N.

In the receiving device 2, first consider performing a deinterleaving operation on the received signal, namely:

Where B ^T is the de-interleaving matrix, satisfying B ^T B = BB ^T = I

that is

in

Since the interleaving matrix has the following properties:

therefore, which is Therefore, in the receiving device 2, the data can be further expressed as follows:

According to the above analysis, the equivalent received signal transmission matrix can be obtained, which cleverly solves the problem that the equivalent channel of each symbol cannot be obtained due to the phase jump processing and the interleaving module, so that the received signal shown in Figure 2 can be obtained The device 2 structure, in order to obtain the estimated value of the transmitted signal, the receiving device 2 needs to perform the same deinterleaving process on the estimated value of the channel response while deinterleaving the data part, so as to accurately obtain the frequency domain space corresponding to the expected symbol of the data The channel matrix completes frequency domain equalization and improves system performance.

The effect of the NGB-W-based multi-antenna multiplexing transmission system of the present invention will be further described below with specific simulation examples and results. During the simulation, please refer to Table 1 for the setting of the simulation parameters.

Table 1 System Simulation Parameters

Please refer to Fig. 3 and Fig. 4 for specific simulation conditions, which are respectively shown as performance curves and graphs of bit error rate and a value under different signal-to-noise ratio conditions in a multi-antenna multiplexing transmission system based on NGB-W of the present invention. A comparison chart of bit error rate performance of traditional SM and an optimized SM system based on an NGB-W-based multi-antenna multiplexing transmission system of the present invention.

It can be seen from Figure 3 that for the scenario where both streams are 64QAM modulation, when traversing the a value of the precoding matrix, in the broadcast highly correlated channel scenario, there is an optimal a value to minimize the performance of the system bit error rate, and, for different The optimized value of a is the same under the signal-to-noise ratio condition, for example, the value is about 2.75 in a 64QAM scenario.

Figure 4 shows the two-antenna multiplexing transmission performance under this optimization angle, which has a greater performance gain than the unprocessed traditional SM. Therefore, for 4, 8, 12 bits/virtual resource element (bpcu) scenarios, that is, the modulation modes of the constellation symbols transmitted on the two antennas are QPSK, 16QAM and 64QAM, we can give the value of parameter a in the orthogonal matrix ,As shown in table 2.

The value of table 2 a

In summary, an NGB-W-based multi-antenna multiplexing transmission system of the present invention achieves the following beneficial effects:

1. The present invention proposes a multi-antenna multiplexing transmission system based on NGB-W multi-antenna multiplexing transmission technology including a transmitting device and a receiving device. By precoding the transmitted signal of the NGB-W system, it includes a constant precoding matrix and The phase jump matrix processing can improve the performance gain under the relevant channel transmission of the broadcast system, obtain space multiplexing and space diversity gain, and can solve the problem that the NGB-W system broadcast cannot obtain a higher transmission rate in the prior art.

2. The values in the precoding matrix processing structure proposed by the present invention are specifically optimized for the NGB-W system, including two-stream transmission scenarios of QPSK, 16QAM and 64QAM, and the optimal bit error rate performance can be obtained.

3. The present invention proposes a multi-antenna demodulation structure of a receiving device based on NGB-W system transmission signals, thereby accurately obtaining the frequency-domain spatial channel matrix corresponding to the expected data symbol, completing frequency-domain equalization, and improving system performance.

Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (5)

1. a kind of multi-antenna multiplexed Transmission system based on NGB-W, the NGB-W is Next generation broadcasting network radio communication system System, the multi-antenna multiplexed Transmission system based on NGB-W includes dispensing device and reception device, it is characterised in that：

The dispensing device includes：

Double antenna mapping block, for brewed string character data sequence to be mapped as into what is transmitted on two parallel antennas Symbol data sequence；

Precoding processing module, is connected with the output end of double antenna mapping block, for the symbol data sequence of input to be carried out Pre-coding matrix processing；

Time-interleaved module, be connected with the output end of precoding processing module, for completing symbol data sequence in time Interweave operation；

Framing module, is connected with the output end of time-interleaved module, for the symbol data sequence after intertexture to be carried out at framing Reason；

Frequency-domain-interleaving module, is connected with the output end of framing module, is handed over for symbol data sequence in subcarrier in frequency domain Knit processing；

OFDM symbol generation module, is connected with the output end of frequency-domain-interleaving module, symbol data sequence completion pilot tone is added, IFFT conversion plus cyclic prefix operation, and be transmitted by the radio frequency unit of two antennas；

The reception device includes：

OFDM demodulation module, is connected with reception antenna, and the baseband signal for the dispensing device to be sent carries out OFDM solutions Mediate reason；

Channel estimation module, is connected with the output end of OFDM demodulation module, and the multi-antenna channel for completing to receive signal declines Fall the estimation of coefficient；

Multi-antenna channel matrix disposal module, is connected with the output end of channel estimation module, for by the multi-path antenna of estimation Space channel value is handled；

Frequency domain de-interleaving block, is connected with the output end of OFDM demodulation module, for receiving symbol data in subcarrier in frequency domain Deinterleaving processing；

Frame extraction module, is connected with the output end of frequency domain de-interleaving block, for frequency domain to be deinterleaved after symbol data sequence Carry out frame extraction process；

Time de-interweaving module, is connected with the output end of frame extraction module, for completing the solution of symbol data sequence in time Interweave operation；

Multiple antennas demodulation module, it is connected with the output end of time de-interweaving module, multi-antenna channel matrix disposal module, profit Frequency domain equalization is carried out to sampled signal with the channel fading coefficient of estimation；

Multiple antennas De-mapping module, it is connected with the output end of multiple antennas demodulation module, for by two antennas of input Parallel symbol data sequence be transformed into serial output symbol data sequence.

2. the multi-antenna multiplexed Transmission system according to claim 1 based on NGB-W, it is characterised in that if will be modulated String character data sequence processed is expressed asThe symbol data sequence then exported is with vector form It is represented byWherein N_{Cells,FEC_block}For the data in each FEC Block The quantity of unit.

3. the multi-antenna multiplexed Transmission system according to claim 2 based on NGB-W, it is characterised in that at precoding Manage in module, by the symbol data sequence z of output_kIt is multiplied with pre-coding matrix w (k), output vector is represented byWherein：

W (k)=D (k) U, k=0,1 ..., N_{Cells,FEC_block}/2-1；

D (k) is that the phase that the cycle is 8 redirects matrix,

U is constant pre-coding matrix,A is constant.

4. the multi-antenna multiplexed Transmission system according to claim 1 based on NGB-W, it is characterised in that in the OFDM In demodulation module, OFDM demodulation processing at least includes going cyclic prefix, FFT operation.

5. the multi-antenna multiplexed Transmission system according to claim 1 based on NGB-W, it is characterised in that at described many days In line channel matrix processing module, include frequency domain deinterleaving, frame for the multi-path antenna space channel value of estimation to be carried out into processing Extract and time de-interweaving.