WO2006131048A1

WO2006131048A1 - An adaptive multi-antenna diversity device and method in the mobile communication network

Info

Publication number: WO2006131048A1
Application number: PCT/CN2006/001001
Authority: WO
Inventors: Xiaolin Zhou; Liyu Cai; Dong Li; Hongwei Yang
Original assignee: Alcatel
Priority date: 2005-06-07
Filing date: 2006-05-17
Publication date: 2006-12-14
Also published as: CN100576769C; CN1878022A

Abstract

An adaptive multi-antenna macro diversity technology in the mobile communication network. Appropriate antennas which belong to one base station or differ base station are selected based on position information of differ regional in the cell in which mobile terminal is; and adaptive complex multi-antenna macro diversity is formed using corresponding adaptive multi-input multi-output (MIMO) transmission technique according to the differ character of channel spatial correlation; thus the invention can reduce adjacent cell interference effectively, acquire more excellent system overall performance than traditional multi-antenna scheme.

Description

Device and method for adaptive multi-antenna diversity in mobile communication network

The present invention relates to mobile communication networks and, more particularly, to techniques for multi-antenna macrodiversity in cellular communication networks. Background technique

With the rapid development of wireless communication technologies, serious shortages of spectrum resources have increasingly become a bottleneck for the wireless communication industry. How to fully exploit and utilize limited spectrum resources and improve spectrum utilization is one of the hotspots in the field of wireless communication. Among them, Multiple Input Multiple Output (MIMO) wireless communication technology is a key technology to improve spectrum utilization in the field of mobile communication.

The concept of Multiple Input Multiple Output (MIMO) wireless communication technology is very simple. Any wireless communication system, as long as multiple antennas or antenna arrays are used at both the transmitting end and the receiving end, constitute a wireless MIMO system. The system uses space-time processing technology for signal processing. In a multipath environment, this technology can multiply the capacity and spectrum utilization of a communication system without increasing bandwidth.

In the prior art, the MIMO technology can be combined with various key parts of the wireless communication system to improve the overall performance of the system, such as combining with coding technology to form space-time coding technology, and combining with modulation technology to form MIMO OFDM technology (; Delete).

Among them, space-time coding technology is a technology based on transmit diversity proposed by Vahid Tarokh et al in 1998. The space-time coding scheme combines channel coding and multi-transmission antennas. The space-time encoded data is serially converted into n data streams. Each data stream is pulse-formed, modulated, and then simultaneously transmitted to the wireless space through n antennas. . At the receiving end, a single antenna or multiple antennas can be used for receiving. Each receiving antenna receives a linear superposition of the n transmitted signals and the interference noise (the fading coefficient is a weight), and then passes the maximum likelihood detection. The method correctly identifies the transmitted signal.

In the existing scheme, there is a transmission scheme of conventional multi-output multi-input adaptive code modulation represented by Severine Catreux and Vinko Erceg, see reference. "Adaptive Modulation and MIMO Coding for Broadband Wireless Data Netoworks"; however, this technology fails to solve the neighbor cell interference problem, resulting in a system transmission bandwidth utilization rate of the MIMO transmission scheme is not high.

In addition, a closed-loop antenna transmit diversity technique is proposed in the 3GPP protocol. Due to the closed-loop design, channel state information feedback is imposed on the system performance, which makes the system have a certain limit on the moving speed of the mobile terminal.

The present invention has been made to solve the above problems existing in the prior art.

The adaptive composite open-loop multi-antenna macro-diversity scheme for the integrated application of space-time coding and spatial multiplexing techniques proposed by the present invention has not been reported yet.

The conventional scheme has lower system capacity and system transmission reliability than the adaptive composite open-loop multi-antenna macro-diversity technology proposed by the present invention.

If adaptive composite open-loop multi-antenna macro-diversity technology is adopted in the cellular radio communication system, the neighbor cell interference can be effectively reduced; at the same time, system capacity and system transmission reliability can be greatly improved. Summary of the invention

The basic idea of the present invention is to construct an adaptive composite (space-time coding or spatial multiplexing) multi-antenna macro by using different multi-output multiple input (MIMO) transmission technologies according to different characteristics of channel spatial correlation in different regions of the cell. The diversity scheme provides better overall system performance than traditional multi-antenna schemes.

Specifically, as shown in FIG. 1, when the mobile terminal is at a non-cell boundary near the base station, the system uses Space Time Coding (STC) Multiple Input Multiple Output (MIMO) transmission technology (eg: Space-time block code) (, to reduce the impact of spatial channel correlation on system performance. The system can also use spatial multiplexing (Spatial Multiple) multiple-output multi-input transmission technology (such as: vertical layered space-time code) to improve system throughput As shown in Figure 2, when the mobile terminal moves to the cell boundary area, in order to suppress neighbor cell interference, the system selects multiple suitable antennas from the base stations around the mobile terminal. The MIMO macro diversity is used to construct a multi-antenna MIMO transmission link between adjacent base stations, so that the signal from the neighboring base station becomes the MIMO useful signal in the new scheme by the neighboring cell interference in the conventional scheme. Thus, at the cell boundary, system macro diversity and MIMO transmission technology are organically combined, and system capacity and link reliability are effectively improved. The MIMO transmission technology can use spatial multiplexing (Various Multiplex) multiple-output multi-input transmission technology (such as: vertical layered space-time code) or space-time coding technology.

According to a first aspect of the present invention, there is provided a method for performing adaptive antenna diversity in a network device of a mobile communication network, comprising the steps of: acquiring location information of a mobile terminal; selecting different according to the location information Antenna diversity; the signal to be transmitted is coded onto the antenna diversity according to a corresponding coding rule.

Preferably, the step of selecting different antenna diversity according to the location information comprises the following steps: if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, selecting multiple antennas of the base station for MIMO transmission And if the location information indicates that the mobile terminal is at a boundary of the base station, selecting at least one antenna in the base station and at least one antenna in the at least one neighboring base station.

More preferably, when the location information indicates that the mobile terminal is at a non-cell boundary of the base station, the corresponding coding rule may be a space time coding technique; and if the location information indicates that the mobile terminal is at the base station At the boundary, the corresponding coding rule may be a spatial multiplexing technique. (This is only a preferred way. As mentioned earlier, the above two MIMO modes can be used when the mobile terminal is at the boundary or non-boundary of the base station)

According to a second aspect of the present invention, there is provided a network device for performing adaptive antenna diversity in a mobile communication network, comprising: a receiving device for receiving location information of a mobile terminal; a selecting device, Selecting different antenna diversity according to the location information; and a code mapping device for mapping the signal to be transmitted to the antenna diversity according to a corresponding coding rule.

Preferably, the selecting means is further configured to: if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, select multiple antennas of the base station; and, if the location information indicates that the mobile terminal is located At the boundary of the base station, at least one antenna in the base station and at least one antenna in at least one neighboring base station are selected. More preferably, when the location information indicates that the mobile terminal is at a non-cell boundary of the base station, the corresponding coding rule may be a space time coding technique; and if the location information indicates that the mobile terminal is at the base station At the boundary, the corresponding coding rule may be a spatial multiplexing technique. (This is only a preferred way. As mentioned before, the above two MIMO modes can be used when the mobile terminal is at the boundary or non-boundary of the base station)

Compared with the prior art, the invention has the following advantages:

1) Compared with the traditional multi-antenna technology, the present invention organically combines multi-antenna multiple-input multiple-output (MIMO) technology with system macro-diversity technology, thereby effectively reducing neighboring cell interference, and system capacity and system availability are obtained. improve.

2) The composite multi-antenna technology designed by the present invention flexibly selects spatial multiplexing or space-time coding technology according to different regions of the user, so that the transmission robustness of space-time coding and the high-band utilization of spatial multiplexing technology are transmitted. The advantages between the two are combined to optimize the overall performance of the system.

3) It is worth mentioning that closed-loop antenna transmit diversity technology has appeared in existing schemes such as 3GPP protocol, and the adaptive composite multi-antenna technology designed by the present invention uses an open-loop scheme, thereby avoiding channel state information feedback to the system. Performance constraints reduce the speed limit of the solution. DRAWINGS

The invention is described in detail below with reference to the drawings, wherein the same or similar reference numerals represent the same parts.

Figures 1 and 2 show a system frame diagram of the present invention;

3 is a schematic diagram showing the operation of a multi-transmit antenna space-time coding scheme according to the present invention;

4 is a schematic diagram showing the operation of a multi-transmit antenna spatial multiplexing coding scheme according to the present invention;

5 is a schematic diagram of a vertical layered space time code scheme in a multi-transmit antenna spatial multiplexing coding scheme according to the present invention;

6 is a diagonal layering in a multi-transmit antenna spatial multiplexing coding scheme according to the present invention. Schematic diagram of a space time code scheme;

7 is a block diagram of a base station controller for performing adaptive antenna diversity in a mobile communication network, in accordance with an embodiment of the present invention;

8 is a flow chart of a method for performing adaptive antenna diversity in a base station controller of a mobile communication network, in accordance with an embodiment of the present invention;

9 is a block diagram of a mobile terminal for performing adaptive antenna diversity in a mobile communication network, in accordance with an embodiment of the present invention;

10 is a flowchart of a method for performing adaptive antenna diversity in a mobile terminal of a mobile communication network, in accordance with an embodiment of the present invention;

11 is a schematic diagram of a system physical layer transmission/reception frame of the present invention; FIG. 12 is a schematic diagram of a simulation system network framework according to the present invention;

13 shows simulation results obtained according to the simulation system network framework shown in FIG. 12; FIG. 14 is a diagram showing simulation results of system band utilization in the cell obtained according to the simulation system network framework shown in FIG.

Figure 15 is a diagram showing simulation results obtained by statistical analysis of signal-to-noise ratios of received signals at various points of a cell obtained according to the network framework of the simulation system shown in Figure 12. detailed description

The present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the invention is not limited to the specific embodiments.

1 and 2 are diagrams showing a system framework of the present invention, including a base station controller 1, a mobile terminal 2, and a plurality of base stations (including a source base station 3 to which the mobile terminal belongs and other neighboring base stations around the mobile terminal). .

In the adaptive composite open-loop multi-antenna macro-diversity scheme of the present invention, first, the mobile terminal 2 continuously measures the signal strength from the source base station 3 and the signal strength from the neighboring base station during the movement. In a period of time, if the signal strength from the source base station 3 is greater than the signal strength of the neighboring base station (or the ratio of the two is greater than a predetermined threshold), the mobile terminal 2 may be determined to be in a non-cell boundary area near the source base station, as shown in the figure. 1; if the signal strength from the source base station 3 is less than or equal to the signal strength of the neighboring base station (or both) The ratio of the ratio is less than a predetermined threshold), then the mobile terminal 2 can be determined to be in the cell boundary area of the source base station, as shown in FIG.

The mobile terminal 2 notifies the source base station 3 of its location information. Subsequently, the source base station 3 notifies the network device (e.g., the base station controller 1) of the location information of the mobile terminal 2. The base station controller 1 selects a plurality of antennas to form a multi-antenna diversity system to transmit signals to the mobile terminal 2 in accordance with the location of the cell in which the mobile terminal is located. Specifically, when the location information indicates that the mobile terminal 2 is in a non-cell border area near its source base station, the base station controller 1 may select multiple antennas of the same base station (source base station 3) to form the multi-antenna diversity system. And when the location information indicates that the mobile terminal 2 is in the cell border region of its source base station, the base station controller 1 may select an antenna of the base station around the mobile terminal (eg, at least one antenna of the source base station 3 and at least one neighboring base station) At least one antenna) is formed to constitute the multi-antenna macrodiversity system.

When the mobile terminal 2 is located at a non-cell boundary near the source base station 3. As described above, the base station controller 1 selects a plurality of antennas of the same base station to transmit signals to the mobile terminal, the multi-antenna wireless channel having a certain spatial correlation. At this time, the system can use the spatial correlation of the channel according to the spatial correlation of the channel, such as space-time coding technology, such as two-shot (two transmit antennas) space time block coding (STBC) ), its working principle is shown in Figure 3:

When a space-time coding scheme is employed, the base station controller 1 maps the MQAM constellation modulation symbols to the two of the source base stations 3.

On the antenna. At the first moment, the first antenna transmits the symbol s _{1 5 and the} second antenna transmits the symbol

S ₂ ; At the second moment, the first antenna transmits the negative conjugate signal of the symbol s ₂ , the second antenna transmits the conjugate signal of the symbol Si; and so on, the two-antenna transmission of the space-time coding of the subsequent symbol is performed.

At this time, since the plurality of antennas are concentrated in the same base station, the antenna elements are separated from each other by more than 4 times of wavelength, thereby reducing the correlation between the transmitting antennas.

When the mobile terminal 2 is located at the cell boundary of the source base station 3, as described above, the plurality of antennas of different base stations selected by the base station controller 1 transmit signals to the mobile terminal, since signals from different base stations experience different propagation paths, The fading process is independent of each other. The mobile terminal combines them to obtain macro points from multiple different path signals. Set gain. Moreover, since the transmit antennas are at different base stations, the spatial channel correlation of the macrodiversity multi-antenna system is small. At this time, an encoding technique that is sensitive to spatial correlation but has a high transmission band utilization, such as spatial multiplexing technology, can be used to increase the communication capacity of the system.

FIG. 4 is a schematic diagram showing the working principle of MQAM constellation modulation symbols mapped to four antennas located in different base stations by multi-antenna spatial multiplexing coding. Mapping is performed on the antenna. The more commonly used is the vertical layered space-time code, as shown in Fig. 5; at this time, the constellation modulation symbols are serial-to-parallel transformed according to the vertical coding matrix, and then mapped to the corresponding antenna for transmission.

Spatial multiplexing coding can also be implemented by diagonal layered space-time codes, as shown in Fig. 6. At this time, the constellation modulation symbols are serial-to-parallel transformed according to the diagonal coding matrix and mapped onto the corresponding antennas.

Figure 7 illustrates a network device (in a conventional base station-base station controller architecture, which may be a base station controller 1) for adaptive antenna diversity in a mobile communication network, in accordance with an embodiment of the present invention.

As shown in Fig. 7, the base station controller 1 includes a receiving device 11, a selecting device 12, a code mapping device 13, and a transmitting device 14.

The receiving device 11 is configured to acquire location information of a mobile terminal. In the base station-base station controller architecture, the location information may include the following information: (1) identification information of the base station to which the mobile terminal belongs;

(2) the mobile terminal is located in the area location information in the cell to which the mobile terminal is located at a non-boundary of the cell or a boundary of the cell;

(3) If the mobile terminal is at the cell boundary, the location information further includes identification information of the neighboring base station and the signal strength indication that the mobile terminal can receive.

In a preferred embodiment, the mobile terminal can measure the signal strength of the neighboring base stations and the identification number of the neighboring base station, from which the mobile station can be identified as the cell edge covered by which base stations. It is to be understood that the method of determining the position information does not constitute a limitation of the present invention.

The selecting means 12 is configured to select different antenna diversity according to the location information. Preferably, if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, the selecting device 12 may select multiple antennas of the base station to form multiple antenna diversity; and if the location information indicates the mobile The terminal is at the boundary of the base station, and the selecting means 12 may select at least one antenna of the base station and at least one of the at least one neighboring base station to form a multi-antenna macrodiversity.

The encoding means 13 is adapted to map the signals to be transmitted onto the antenna diversity in accordance with respective encoding rules. Preferably, if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, the code mapping device 13 may employ a coding technique that is not sensitive to spatial correlation, such as space time coding technology, to transmit the desired transmission. Signal coding is mapped onto the antenna diversity; and if the location information indicates that the mobile terminal is at a cell boundary of the base station, the code mapping device 13 may employ spatial correlation sensitivity but high transmission band utilization. Encoding techniques, such as spatial multiplexing techniques, map the signal to be transmitted onto the antenna diversity.

The transmitting device 14 is configured to transmit the encoded signal to the base station of the antenna diversity.

8 illustrates a method for adaptive antenna diversity in a network device of a mobile communication network (in a conventional base station-base station controller architecture, which may be a base station controller) in accordance with an embodiment of the present invention.

As shown in the figure, in step S101, location information of a mobile terminal is obtained. In the base station-base station controller architecture, the location information may include the following information: (1) identification information of the base station to which the mobile terminal belongs;

In a preferred embodiment, the mobile terminal can measure the signal strength of the neighboring base station and the identification number of the neighboring base station, from which the mobile station can be identified as the cell edge covered by which base stations. It is to be understood that the method of determining the position information does not constitute a limitation of the present invention. In a preferred embodiment, the mobile terminal may first report its location information to the source base station; the source base station then notifies the base station controller of the location information of the mobile terminal and the source base station itself.

Subsequently, in step S102, different antenna diversity is selected based on the location information. Preferably, if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, multiple antennas of the base station may be selected to form multiple antenna diversity; and if the location information indicates that the mobile terminal is at the boundary of the base station At least one of the antennas and at least one of the at least one neighboring base station may be selected to form a multi-antenna macrodiversity.

Subsequently, in step S103, the signal to be transmitted is code mapped onto the antenna diversity according to a corresponding encoding rule. Preferably, if the location information indicates that the mobile terminal is at a non-cell boundary of the base station, an encoding technique that is not sensitive to spatial correlation, such as space time coding technology, may be employed to map the signal to be transmitted to the On the antenna diversity; if the location information indicates that the mobile terminal is at the cell boundary of the base station, an encoding technique that is sensitive to spatial correlation but high in transmission band utilization, such as spatial multiplexing technology, is used to transmit The signal code is mapped onto the antenna diversity.

In step S104, a signal encoded according to the corresponding encoding rule is transmitted to the base station to which the selected antenna diversity belongs. The base station will control the corresponding antenna in the selected antenna diversity to transmit a coded signal to the mobile terminal.

Figure 9 illustrates a mobile terminal 2 for performing adaptive antenna diversity in a mobile communication network in accordance with an embodiment of the present invention. As shown in Fig. 9, the mobile terminal 2 includes a detecting device 21, a judging device 22, a transmitting device 23, a receiving device 24, and a synthesizing device 25.

The detecting device 21 is configured to detect a signal strength from a home base station and a signal strength from a neighboring base station.

The determining device 22 is configured to determine, according to a signal strength of the home base station and a signal strength from the neighboring base station, a location of the mobile terminal in the home base station. Specifically, as described above, if the signal strength from the source base station 3 is greater than the signal strength of the neighboring base station for a period of time (or the ratio of the two is greater than a predetermined threshold), the non-determination of the mobile terminal 2 near the source base station can be determined. Cell boundary area; if from source base station 3 If the signal strength is less than the signal strength of the neighboring base station for a period of time (or the ratio of the two is less than a predetermined threshold), then the mobile terminal 2 can be determined to be in the cell boundary region of the source base station.

The transmitting device 23 is configured to send the determination result to the base station controller 1. In practice, the mobile terminal 2 may first send the determination result to the source base station 2, and then the source base station.

2 Notifying the base station controller 1 of the location information.

The receiving device 24 is for receiving encoded signals from different antennas. These antennas are multi-antenna diversity selected by the base station controller based on the location of the mobile terminal in its associated base station.

The synthesizing means 25 is operative to synthesize the encoded signals from different antennas into an output signal according to decoding rules corresponding to encoding rules at the network device.

Since in the present invention, the base station controller 1 will select a different coding method according to the location of the mobile terminal 2 in its own base station to map the signal to be transmitted to the selected antenna diversity. Therefore, in order to be able to restore the original signal from the received coded signals from different antennas, the mobile terminal 2 also needs to know the coding rules employed by the base station control 1. In a preferred embodiment, the encoding rules currently employed by the base station controller 1 can be transmitted to the mobile terminal 2 via the downlink channel through the source base station to which the mobile terminal 2 belongs. Figure 10 illustrates a method for adaptive antenna diversity in a mobile terminal of a mobile communication network in accordance with an embodiment of the present invention.

As shown, in step S201, the signal strength from the home base station and the signal strength from the neighboring base station are detected.

Then, in step S202, the location of the mobile terminal in the home base station is determined according to the signal strength of the home base station and the signal strength from the neighboring base station. Specifically, as described above, if the signal strength from the source base station 3 is greater than the signal strength of the neighboring base station for a period of time (or the ratio of the two is greater than a predetermined threshold), the non-cell of the mobile terminal 2 in the vicinity of the source base station may be determined. The boundary region; if the signal strength from the source base station 3 is less than the signal strength of the neighboring base station for a period of time (or the ratio of the two is less than a predetermined threshold), the mobile terminal can be determined to be in the cell boundary region of the source base station.

Then, in step S203, the determination result is sent to a network device. In practice, the mobile terminal may first send the determination result to the source base station 2, and then the source base station 2 notifies the base station controller 1 of the location information.

Subsequently, in step S204, encoded signals from different antennas are received. These antennas are multi-antenna diversity selected by the base station controller based on the location of the mobile terminal in the base station to which it belongs.

Finally, in step S205, the encoded signals from the different antennas are synthesized into an output signal according to a decoding rule corresponding to the encoding rule at the network device.

Since in the present invention, the base station controller 1 will select a different coding method according to the location of the mobile terminal 2 in its own base station to map the signal to be transmitted to the selected antenna diversity. Therefore, in order to be able to restore the original signal from the received coded signals from different antennas, the mobile terminal 2 also needs to know the coding rules employed by the base station control 1. In a preferred embodiment, the coding rules currently employed by the base station controller 1 can be transmitted to the mobile terminal 2 via the downlink channel via the source base station to which the mobile terminal 2 belongs. Experimental result

According to the above design concept, we have designed an embodiment of a wideband OFDM adaptive composite open-loop multi-antenna macro-diversity system. The system architecture is shown in Figure 1 and Figure 2. Figure 11 shows the system physical layer transmit/receive frame of the present invention.

As shown in Figure 11, first, the serial source data from the MAC layer is subjected to Turbo coding and MQAM modulation. Thereafter, the space-time coding or spatial multiplexing coding module maps the constellation modulation symbol packets to the spatial domain and the time domain, generates an orthogonal sequence, and further maps to N subcarriers of the OFDM system. In addition, in order to improve the system's ability to resist intersymbol interference, the complex signal is inserted into the cyclic prefix, and parallel-to-serial conversion, shaping filtering, and D/A conversion are performed. Finally, it is transmitted through the antenna.

At the receiving end, the system performs A/D conversion, shaping filtering, serial-to-parallel conversion, and de-circulating prefix. Then, multi-carrier demodulation and time-frequency subcarrier demapping are performed. And linear processing is used to obtain the maximum likelihood decoding of the space-time block code (or spatial multiplexing decoding), and then through the constellation soft demodulation and decoding module. Finally, the system will get an estimate of the information sequence.

The following is mainly for the signal-to-noise ratio performance of the system receiving signal in this embodiment, and the system bandwidth The utilization rate and system availability are compared with the performance of the traditional multi-input multi-output orthogonal frequency division system. Figure 12 shows a simulation system framework of a cellular communication network model employing 19 base stations in accordance with the present invention. The model can effectively reflect and analyze the signal interference between base stations, and is a general system capacity simulation network architecture. Figure 12 shows a simulation system network framework in accordance with the present invention.

The simulation system parameters are as follows:

(1) Cellular system network with 19 base stations

(2) The physical layer uses broadband orthogonal frequency division multiplexing technology, including 1024 subcarriers.

(3) System block error rate performance is less than 0.01

(4) Carrier frequency is 3.2G Hertz

(5) Base station transmit power is 40dBm

(6) Transmitting antenna gain is 7dBi

(7) Thermal noise spectral density is -174dBm/Hz

(8) The noise bandwidth is 10MHz

(9) The standard deviation of shadow fading is 5dB

(10) Path loss model [Pathloss=37*logl0 (distance)+20*logl0 (carrier frequency) +43.58] Simulation conclusion 1 as shown in Figure 13: (The left picture does not consider shadow fading, the right picture considers shadow fading)

As shown in Figure 13, at the cell boundary, without considering shadow fading, the adaptive composite multi-antenna macro-diversity technique has a signal-to-noise ratio higher than 6 dB, while the conventional multi-antenna scheme has a received signal-to-noise ratio lower than 6 dB. , even less than OdB. Under the same simulation conditions, if the shadow fading is considered, the signal-to-noise ratio of the received signal of the adaptive composite multi-antenna macro-diversity technique is still higher than that of the traditional multi-antenna scheme. Therefore, the adaptive composite multi-antenna macro-division technique proposed by the present invention can obtain a superior received signal-to-noise ratio (SNR) signal quality.

Simulation Conclusion 2:

Figure 14 is a simulation diagram of the system band utilization in the cell (the simulation on the left is traditional) Multi-antenna system, the right simulation picture is adaptive composite multi-antenna macro diversity scheme)

FIG I ^4, the adaptive multi-antenna complex macro diversity scheme proposed by the present invention in the cell boundary to obtain higher bandwidth efficiency performance.

Simulation Conclusion 3:

Figure 15 shows the results of statistical analysis of the signal-to-noise ratio of received signals at various points in the cell. It can be seen from Fig. 15 that the adaptive composite multi-antenna macro diversity scheme proposed by the present invention obtains a superior signal reception signal-to-noise ratio cumulative probability distribution.

Simulation Conclusion 4: (System Cell Average Band Utilization and System Effectiveness Simulation)

In order to simulate the average frequency band utilization and system effectiveness performance of the cell in the system framework shown in FIG. 12, the present invention designs two sets of coding modulation schemes, and the first scheme is an adaptive coding modulation scheme at a non-cell boundary, and the simulation result thereof The following is shown in Table 1; The second set of schemes is an adaptive coding modulation scheme at the cell boundary, and the simulation results are shown in Table 2 below. Note: The coded modulation scheme in this simulation is only for system performance analysis. In practical engineering applications, it can be selected or designed separately according to the actual situation. Table 1: Adaptive coded modulation scheme at non-cell boundary Adaptive coded modulation mode Band utilization

(2X2 STBC scheme at non-cell boundary) (Bps/Hz) (dB)

Mode 1 Cut-off 0 SINR<-3.5 Mode 2 1/16 Turbo code Encoding QPSK 0.125 -3.5<SINR<0.5

Modulation 2X2 STBC

Mode 3 1/4 Turbo code Encoding QPSK 0.5 0.5<SINR<3.5

Modulation 2X2 STBC

Mode 4 1/2 Turbo code Encoding QPSK 1.0 3.5<SINR<7.0

Modulation 2X2 STBC

Mode 5 3/8 Turbo code Encoding 16QAM 1.5 7.0<SINR<10.5

Modulation 2X2 STBC

Mode 6 1/3 Turbo code Encoding 64QAM 2.0 10.5<SINR<14.0

Modulation 2X2 STBC

Mode 7 1/2 Turbo code Encoding 64QAM 3.0 SINR>14.0

Modulation 2X2 STBC Table 2: Adaptive Code Modulation Scheme at Cell Boundary

The simulation conclusions can be drawn from Tables 1 and 2 as follows:

The adaptive composite multi-antenna macro-diversity scheme proposed by the present invention can obtain a system average frequency band utilization of 1.28 bps/Hz/Cell and 96% when the cell radius is 1000 m and the above adaptive code modulation scheme is used. System availability.

Under the same simulation system parameters, the traditional multi-antenna system can be obtained.

System average band utilization of 0.973 bps/Hz/Cell and 76% system availability.

It will be apparent that the adaptive composite multi-antenna macrodiversity scheme proposed by the present invention can achieve higher system average band utilization and system effectiveness performance. The specific embodiments of the present invention have been described above. It is to be understood that the invention is not limited to the specific embodiments described above, and various modifications and changes can be made by those skilled in the art within the scope of the appended claims.

Claims

Rights request

A method for performing adaptive antenna diversity in a network device of a mobile communication network, comprising the steps of:

Obtaining location information of a mobile terminal;

Selecting different antenna diversity according to the location information;

The signal code to be transmitted is mapped onto the antenna diversity according to a corresponding encoding rule.

2. The method of claim 1 wherein

The step of selecting different antenna diversity according to the location information includes the following steps: If the location information indicates that the mobile terminal is at a non-cell boundary of the base station, selecting multiple antennas of the base station for MIMO transmission.

If the location information indicates that the mobile terminal is at the boundary of the base station, at least one antenna of the base station and at least one of the at least one neighboring base station are selected for MIMO transmission.

3. Method according to claim 1 or 2, characterized in that

The encoding rules include space time coding techniques and spatial multiplexing techniques.

4. The method of claim 3, wherein

If the location information indicates that the mobile terminal is at a non-cell boundary of the base station, the corresponding coding rule may be a space time coding technique.

5. Method according to claim 3 or 4, characterized in that

If the location information indicates that the mobile terminal is at the boundary of the base station, the corresponding coding rule may be a spatial multiplexing technique.

The method according to any one of claims 1 to 5, wherein the location information comprises:

- identification information of the base station to which the mobile terminal belongs;

- the mobile terminal is in area location information within the cell to which the mobile terminal is located at a non-boundary of the cell or at the boundary of the cell;

- if the mobile terminal is at the cell boundary, the location information also includes the mobile terminal The identification information of the received neighboring base station and its signal strength indication.

7. A network device for performing adaptive antenna diversity in a mobile communication network, comprising:

a receiving device, configured to receive location information of a mobile terminal;

a selecting means for selecting different antenna diversity based on the position information; and a code mapping means for mapping the signal to be transmitted to the antenna diversity according to a corresponding encoding rule.

8. The network device according to claim 7, wherein

The selection device is also used to:

If the location information indicates that the mobile terminal is at a non-cell boundary of the base station, selecting multiple antennas of the base station for MIMO transmission;

9. The network device according to claim 7 or 8, wherein

10. The network device according to claim 9, wherein

The network device according to claim 9 or 10, wherein if the location information indicates that the mobile terminal is at a boundary of the base station, the corresponding coding rule may be a spatial multiplexing technique.

The method according to any one of claims 7-11, wherein the location information comprises:

- If the mobile terminal is at the cell boundary, the location information further includes identification information of the neighboring base station and the signal strength indication that the mobile terminal can receive.