CN102739282A - Multi-antenna combined detection system of TD-SCDMA system and multi-antenna combined detection method thereof - Google Patents

Abstract

The invention relates to a multi-antenna combined detection system of a TD-SCDMA system and a multi-antenna combined detection method thereof. The detection system comprises a plurality of antennas, a plurality of data separation units, a plurality of channel estimation units, a channel estimation postprocessing unit and a combined detection unit. All the antennas are used for receiving signals. The data separation units, which are respectively connected with the antennas, are used for separating training sequences and to-be-demodulated data in the received signals of the corresponding antennas. All the channel estimation units that are respectively connected with the data separation units are used for carrying out channel estimation by utilizing the training sequences. The channel estimation postprocessing unit utilizes channel estimation results of the plurality of channel estimation units to generate a channel system matrix. And the combined detection unit utilizes the channel system matrix and the to-be-demodulated data to calculate estimation values of useful signals in the received signals.

Description

The many antennas combined detection system and the method thereof of TD-SCDMA system

Technical field

The present invention relates to the TD-SCDMA system, especially relate to many antennas combined detection system of TD-SCDMA system.

Background technology

Along with development of wireless communication devices and 3G rise in the world, Radio Resource do not become more and more nervous as a kind of Limited resources.For the TD-SCDMA system of one of 3G mainstream standard, its Radio Resource that is assigned with also is very limited.In order to improve the availability of frequency spectrum of TD-SCDMA system, identical networking becomes a kind of effective solution.But identical networking also brings with disturbing frequently when improving spectrum efficiency.With disturbing the different districts inter-user interference that is meant that adjacent cell causes because of using identical carrier frequency, identical spreading factor to carry out transfer of data frequently.With interference frequently various aspects of performance such as power system capacity and communication quality are all descended to some extent.

Belong to a kind of of multiple access interference (MAI) with disturbing frequently.The TD-SCDMA system adopts joint detection algorithm to overcome multiple access and disturbs (MAI).Simultaneously, can disturb stronger adjacent area and also bring joint-detection into through estimating the channel impulse response of adjacent area, disturb thereby eliminate stronger adjacent area for the interference of adjacent area.

Yet from the consideration of factors such as implementation complexity, present joint detection algorithm adopts single antenna to handle at present, and the maximum code channel number of support is 16.When the adjacent area interference source is more, total code channel number will inevitably appear greater than 16 situation.At this moment, understand some code channel and can't participate in joint-detection, cause to eliminate this part multiple access and disturb.

Summary of the invention

The objective of the invention is to propose the many antennas combined detection system and the method for a kind of TD-SCDMA system, under situation about increasing, still can eliminate with multiple access frequently and disturb at code channel number.

Many antennas combined detection system of a kind of TD-SCDMA proposed by the invention system comprises a plurality of antennas, a plurality of data separating unit, a plurality of channel estimating unit, a channel estimating post-processing unit and a joint-detection unit.Each antenna is used for receiving signal.Each data separating unit connects an antenna respectively, in order to training sequence in the reception signal of respective antenna and data separating to be demodulated.Each channel estimating unit connects a data separating unit respectively, carries out channel estimating in order to utilize this training sequence.The channel estimating post-processing unit utilizes the channel estimation results of a plurality of channel estimating unit, generates the channel system matrix.This channel system matrix of joint-detection unit by using and this data to be demodulated are calculated the estimated value that receives the useful signal in the signal.

In one embodiment of this invention, each antenna is supported a predetermined number code channel.

In one embodiment of this invention, the code channel number of joint-detection is participated in this joint-detection unit restriction, makes code channel number be less than or equal to this channel system rank of matrix.

In one embodiment of this invention, this joint-detection unit limits the code channel number of participating in joint-detection through the thresholding that improves the code channel activating detection.

In one embodiment of this invention, the number of said antenna, data separating unit and channel estimating unit is two.

In one embodiment of this invention, the estimated value of this useful signal is that Minimum Mean Square Error is estimated.

The present invention proposes many antennas associated detecting method of a kind of TD-SCDMA system in addition, and may further comprise the steps: utilize a plurality of antenna receiving signals, this reception signal comprises training sequence and data to be demodulated; Reception signal to each antenna carries out data separating, to obtain training sequence and data to be demodulated respectively; Utilize this training sequence that each antenna is carried out channel estimating; Reprocessing is carried out in channel estimation results merging to a plurality of antennas, to obtain a channel system matrix; And utilize this channel system matrix and this data to be demodulated, calculate the estimated value that receives the useful signal in the signal.

In one embodiment of this invention, each antenna is supported a predetermined number code channel.

In one embodiment of this invention, also comprise the code channel number of restriction participation joint-detection, make code channel number be less than or equal to this channel system rank of matrix.

In one embodiment of this invention, be to limit the code channel number of participating in joint-detection through the thresholding that improves the code channel activating detection.

In one embodiment of this invention, said number of antennas is two.

In one embodiment of this invention, the estimated value of this useful signal is that Minimum Mean Square Error is estimated.

Compare the combined detection system of prior art; The combined detection system of many antennas proposed by the invention; Both can improve receptivity through diversity reception; Can improve anti-ability through spatial reuse again, thereby from receive signal, isolate useful signal more exactly, and then significantly improve the demodulation performance that receives signal with frequency.

Description of drawings

For let above-mentioned purpose of the present invention, feature and advantage can be more obviously understandable, elaborate below in conjunction with the accompanying drawing specific embodiments of the invention, wherein:

Fig. 1 illustrates according to an embodiment of the invention, and double antenna receives baseband model.

Fig. 2 illustrates the combined detection system of one embodiment of the invention.

Fig. 3 illustrates the associated detecting method of one embodiment of the invention.

Embodiment

Be the description that example is carried out detail with the TD-SCDMA wireless communication system below, so that the overall understanding to many antennas combined detection system of the present invention is provided.Describing for simplifying, will be example with two antennas in the following description.Comprise the situation of unnecessary two antennas for system, its model is similar with the following model that will describe.

Fig. 1 illustrates system's baseband model according to an embodiment of the invention, wherein, and e ₁And e ₂Be respectively the data to be demodulated of the reception of two antennas.A ⁽¹⁾And A ⁽²⁾Be respectively two channel system matrixes on the antenna, in its neutron piece

The channel vector of representing i code channel on the j root antenna.J symbol on i code channel of

expression.n ₁And n ₂Expression receives the white Gaussian noise that comprises in the signal, n respectively _iBe that variance is σ ²And Normal Distribution N (0, σ ²) white Gaussian noise.

In the TD-SCDMA wireless communication system, the data to be demodulated that receive in the signal can be defined as usually:

e＝A·d+n (1.1)

Wherein A is the channel system matrix, and d is a useful signal, and n is for receiving the white Gaussian noise that comprises in the signal.

Can know that by baseband model with respect to single antenna, the channel system matrix that double antenna receives expands to:

$A=\left[\begin{array}{c}{A}^{\left(1\right)}\\ A^{\left(2\right)}\end{array}\right];$

Data to be demodulated expand to:

$e=\left[\begin{array}{c}{e}^{\left(1\right)}\\ e^{\left(2\right)}\end{array}\right];$

Receiving the white Gaussian noise that comprises in the signal expands to:

$n=\left[\begin{array}{c}{n}_1\\ {\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000053800400000011.png"\; state="\{\{state\}\}">n</figure-callout>}}_2\end{array}\right].$

As the result of two antenna joint-detection, similar with the principle of single antenna joint-detection, the Minimum Mean Square Error of useful signal d (MMSE) is estimated as:

$\hat{d}={(A^{H}A+{\mathrm{\&sigma;}}^{2}I)}^{-1}{A}^{H}e---\left(1.2\right)$

Wherein,

The Minimum Mean Square Error of expression useful signal d is estimated A ^HThe conjugate transpose of expression channel system matrix A, I representation unit matrix.

The system of the joint-detection of many antennas having thus described the invention is to integrate multi-antenna diversity to receive and spatial reuse.It both can improve receptivity through diversity reception, can improve anti-ability with frequency through spatial reuse again, thereby from receive signal, isolate useful signal more exactly, and then significantly improve the demodulation performance that receives signal.Specifically, when total code channel number of joint-detection was lower than 16 code channels, this system was equivalent to a multi-antenna diversity receiving system, obtains good diversity gain; When total code channel number of joint-detection was 32 code channels, this system was equivalent to a space multiplexing system, supported 32 code channels to participate in joint-detection simultaneously; And when code channel number was between 16 and 32, then existing diversity gain had spatial multiplexing gain (anti-with ability frequently) again.

Based on above analysis, a combined detection system according to an embodiment of the invention as shown in Figure 2 is described.As shown in Figure 2, this combined detection system 200 comprises: 201,202, two data separative elements of two antennas 211,212, two channel estimating unit 221,222, channel estimating post-processing unit 230 and joint-detection unit 240.Corresponding No. one antenna of each data separating unit and channel estimating unit.For example, the first data separating unit 211 and first channel estimating unit, 221 corresponding first antennas 202; The second data separating unit 212 and second channel estimation unit 222 corresponding second antennas 202.

Specifically, two data separative elements 211,212 are used for separating training sequence and the data to be demodulated from the signal that two antennas 201,202 receive respectively.

Two channel estimating unit 221,222 utilize training sequence to carry out channel estimating.

Channel estimating post-processing unit 230 utilizes the channel estimation results of two channel estimating unit 221,222, generates the channel system matrix A.At this, the channel system matrix A is just as shown in Figure 1, by the channel system matrix A of two antennas ⁽¹⁾And A ⁽²⁾Combine.

Joint-detection unit 240 utilizes channel system matrix and data to be demodulated, and the Minimum Mean Square Error estimation

of calculating the useful signal in the reception signal is used for the follow-up mediation of separating and deciphers.

Accordingly, Fig. 3 illustrates the associated detecting method of one embodiment of the invention.With reference to shown in Figure 3, at step S300, utilize a plurality of antenna receiving signals, then at step S301, the reception signal of each antenna is carried out data separating, separate wherein training sequence and data to be demodulated.At step S302, utilize training sequence that each antenna is carried out channel estimating.At step S303, reprocessing is carried out in the channel estimation results merging of a plurality of antennas, then to obtain the channel system matrix A.At last; At step S304; Utilize channel system matrix and data to be demodulated, calculate the Minimum Mean Square Error estimation of useful signal

Though provided the embodiment that joint-detection adopts Minimum Mean Square Error to estimate above it should be noted that, should be able to recognize that communication system of the present invention and subscriber equipment are not limited to this example, but can adopt additive method to estimate.

In addition, in Project Realization, can't guarantee that the data that two antennas receive are independent fully.Correlation of data means that the channel system matrix A is not a full rank between the antenna, and this moment, the decomposition of correlation matrix was unsettled, thereby made for the demodulation performance variation that receives signal.Therefore, need avoid this situation,, make code channel number be less than or equal to rank of matrix, guarantee the stable of matrix decomposition such as the code channel number of joint-detection unit 240 through restriction participation joint-detection through increasing some safeguard measures.In one embodiment, joint-detection unit 240 can prevent the more situation of code channel number that the code channel activating erroneous detection is caused through improving the thresholding that code channel activating detects.

Compare with the frequency combined detection system with conventional single-antenna; The channel estimating post-processing unit of the described many antennas combined detection system of the embodiment of the invention is exported the channel system matrix of two antennas simultaneously, and the channel system matrix that makes the joint-detection unit can unite two antennas carries out MIMO and detects; And owing to adopt MIMO to detect, joint-detection can detect the data of more code channels.With two antennas is example, can detect the data of 32 code channels at most.

Therefore; Compare conventional single-antenna with the frequency combined detection system, many antennas combined detection system of the embodiment of the invention has stronger joint-detection ability, improves to resist together interference capability frequently; And under the situation of the non-full rank of channel system matrix, there is certain diversity gain in system.In addition, this many antennas combined detection system can be considered the system that a MIMO combines joint-detection in fact, can be to MIMO-CDMA system smooth evolution.

Though the present invention discloses as above with preferred embodiment; Right its is not that any those skilled in the art are not breaking away from the spirit and scope of the present invention in order to qualification the present invention; When can doing a little modification and perfect, so protection scope of the present invention is when being as the criterion with what claims defined.

Claims (12)

1. many antennas combined detection system of a TD-SCDMA system comprises:

A plurality of antennas;

A plurality of data separating unit, each data separating unit connects an antenna respectively, in order to training sequence in the reception signal of respective antenna and data separating to be demodulated;

A plurality of channel estimating unit, each channel estimating unit connect a data separating unit respectively, carry out channel estimating in order to utilize this training sequence;

The channel estimating post-processing unit utilizes the channel estimation results of a plurality of channel estimating unit, generates the channel system matrix;

The joint-detection unit utilizes this channel system matrix and this data to be demodulated, calculates the estimated value that receives the useful signal in the signal.

2. the system of claim 1 is characterized in that, each antenna is supported a predetermined number code channel.

3. the system of claim 1 is characterized in that, the code channel number of joint-detection is participated in this joint-detection unit restriction, makes code channel number be less than or equal to this channel system rank of matrix.

4. system as claimed in claim 3 is characterized in that, this joint-detection unit limits the code channel number of participating in joint-detection through the thresholding that improves the code channel activating detection.

5. the system of claim 1 is characterized in that, the number of said antenna, data separating unit and channel estimating unit is two.

6. the system of claim 1 is characterized in that, the estimated value of this useful signal is that Minimum Mean Square Error is estimated.

7. many antennas associated detecting method of a TD-SCDMA system may further comprise the steps:

Utilize a plurality of antenna receiving signals, this reception signal comprises training sequence and data to be demodulated;

Reception signal to each antenna carries out data separating, to obtain training sequence and data to be demodulated respectively;

Utilize this training sequence that each antenna is carried out channel estimating;

Reprocessing is carried out in channel estimation results merging to a plurality of antennas, to obtain a channel system matrix; And

Utilize this channel system matrix and this data to be demodulated, calculate the estimated value that receives the useful signal in the signal.

8. method as claimed in claim 7 is characterized in that, each antenna is supported a predetermined number code channel.

9. method as claimed in claim 7 is characterized in that, also comprises the code channel number of restriction participation joint-detection, makes code channel number be less than or equal to this channel system rank of matrix.

10. method as claimed in claim 9 is characterized in that, limits the code channel number of participating in joint-detection through the thresholding that improves the code channel activating detection.

11. method as claimed in claim 7 is characterized in that, said number of antennas is two.

12. method as claimed in claim 7 is characterized in that, the estimated value of this useful signal is that Minimum Mean Square Error is estimated.

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