FR2968866A1 - Method for transmitting data signals using multiple antennas in digital broadcast communications, involves performing process of diversity allocation of data signal and another data signal with regard to antennas for providing diversity - Google Patents

Abstract

The method involves executing a process on a diversity encoded data signal, and executing another process on another diversity encoded data signal. One of the data signal is coupled with another data signal after being subjected to diversity process. The former and the latter encoded data signals are transmitted via multiple antennas (250). A process of diversity allocation of the former data signal and the latter data signal is performed with regard to the antennas for providing diversity. An independent claim is also included for a device for transmitting data signals using multiple antennas.

Description

METHOD AND DEVICE FOR TRANSMITTING DATA SIGNALS USING MULTIPLE ANTENNAS

The present invention relates to a method for transmitting data signals, and more particularly to a method for transmitting auxiliary data with main data in digital communications or in digital broadcast communications. In the field of broadcast data transmissions, a method for transmitting auxiliary data together with main data is considered. In an auxiliary data insertion method that is currently considered, data is transmitted using a single antenna. More specifically, in broadcast systems and / or communication systems, ancillary data having a strong autocorrelation and long low power codes are inserted into main data and are transmitted together with them. In this case, this causes a decrease in the system capacity and the coverage of the broadcast and the communication is thus reduced. An advantage of some aspects of the invention is that it provides an efficient method for transmitting main data and auxiliary data. Another advantage of some aspects of the invention is that it provides a method which can increase the transmission efficiency of the main data using a diversity technique and improve the transmission speed and capacity. auxiliary data with this technique.

Yet another advantage of some aspects of the invention is that it provides a stable method for transmitting auxiliary data together with the main data. One aspect of the invention relates to a method of transmitting data signals using multiple antennas comprising: performing a diversity process on a first coded and modulated data signal; performing a diversity process on a second coded and modulated data signal; coupling together the first data signal having been subjected to the diversity process and the second data signal having been subjected to the diversity process; and transmitting the first and second coupled data signals via the multiple antennas. In this case, the diversity process includes a process of assigning the first data signal and the second data signal to antennas among the multiple antennas to obtain the diversity. The transmission power of the second data signal can be increased based on a diversity gain of the first data signal. A code length of the second data signal may be decreased based on an increased value of the transmission power. The transmission power of the second data signal can be increased based on the quality of service of a transmission channel. The second data signal may include a plurality of different auxiliary data signals, and the plurality of auxiliary data signals may be respectively assigned to the antennas of the multiple antennas by the use of the diversity process on the second data signal. In this case, at least one of the plurality of different auxiliary data signals can be assigned to each antenna of the multiple antennas. The number of different auxiliary data signals can be increased according to the diversity gain of the first data signal. The transmission power can be set to be different between the different auxiliary data signals. The method of transmitting data signals may further comprise receiving feedback information on a state of a transmission channel through which the first data signal and the second data signal are transmitted. In this case, only the second data signal, assigned to the antennas having a good channel state among the second data signal having been subjected to the diversity process, may be coupled to the corresponding first data signal from the first data signal having been submitted to the diversity process and be transmitted with it.

The diversity process used to transmit the first data signal and the second data signal may be one of the following techniques: space-time block coding (STBC), delay diversity (DD), cyclic delay diversity (CDD) , space-frequency block coding (SFBC), spatial multiplexing, cooperative transmission between macro base stations, cooperative transmission between a macro base station and a micro base station, and cooperative transmission between transmitters. Another aspect of the invention relates to a data signal transmission device comprising: a first diversity processing unit that executes a diversity process on a first coded and modulated data signal; a second diversity processing unit that performs a diversity process on a second coded and modulated data signal; a plurality of signal coupling units which couple signals transmitted from the first diversity processing unit and from the second diversity processing unit; and a plurality of transceiver units which receive signals from the signal coupling units and send the signals to the corresponding antennas among the multiple antennas constituting a multiple antenna system. In this case, the diversity process comprises a process of assigning the first data signal and the second data signal to the antennas of the multiple antennas in order to have the diversity, and the plurality of signal coupling units and the plurality transmission-reception units correspond uniquely to the antennas of the multiple antenna system.

The transmission power of the second data signal can be increased based on a diversity gain of the first data signal. The second data signal may comprise a plurality of different auxiliary data signals and the second diversity processing unit may execute the diversity process respectively on the different auxiliary data signals. Each transceiver unit may receive feedback information on a state of a transmission channel through which the first data signal and the second data signal are transmitted. In this case, the signal coupling units can couple only the second data signal, assigned to the antenna having a good channel state, from the second data signal having been subjected to the diversity process, to the corresponding first data signal. from the first data signal having been submitted to the diversity process on the basis of the feedback information and can send the coupled signal to the corresponding transceiver unit to the antenna having a good channel state. According to the aforementioned configurations of the invention, it is possible to efficiently transmit main data and auxiliary data. It is also possible to increase the efficiency of the main data transmission using a diversity technique and to improve the transmission speed and the capacity of the auxiliary data with this technique. It is also possible to stably transmit auxiliary data together with main data. Other features and advantages of the invention will emerge more clearly on reading the description below, made with reference to the accompanying drawings. Fig. 1 is a diagram schematically illustrating the insertion of auxiliary data into a main data frame to jointly transmit main data and auxiliary data. Figure 2 is a diagram schematically illustrating the transmission of data from a transmitting terminal using multiple antennas. Fig. 3 is a diagram schematically illustrating an example in which transmitters of a broadcast system perform cooperative transmission to gain diversity gain.

Fig. 4 is a diagram schematically illustrating an example in which a macro base station and a micro base station located in the macro base station perform cooperative transmission to gain diversity gain.

FIG. 5 is a diagram illustrating the comparison of a Bit Error Rate (BER) when using a space-time block coding (STBC) process with case using a single antenna.

Fig. 6 is a block diagram schematically illustrating the configuration of a device or system for transmitting data signals according to an embodiment of the invention. Fig. 7 is a diagram schematically illustrating a method of inserting an auxiliary data signal into a frame according to which a main data signal is transmitted according to an embodiment of the invention. Fig. 8 is a diagram schematically illustrating another method of inserting an auxiliary data signal into a frame according to which a main data signal is transmitted according to an embodiment of the invention. Fig. 9 is a diagram schematically illustrating another method of inserting an auxiliary data signal into a frame according to which a main data signal is transmitted according to an embodiment of the invention. Fig. 10 is a flow chart schematically illustrating a method of transmitting a data signal in a transmission system according to an embodiment of the invention. Embodiments of the invention given by way of example will be described in detail below with reference to the accompanying drawings. It should be noted that when assigning a reference number to elements in the drawings, identical elements have received as much as possible the same reference number even if they are illustrated in different drawings. When it is determined in the description of embodiments of the invention that a specific description of known configurations or functions renders the concept of the invention vague, it will be omitted from a detailed description thereof. The terms "first", "second", "A", "B", "(a)" and "(b)" may be used to explain items in this memo. Such terms are intended only to distinguish an element from another element, and the nature, sequence or order of the corresponding elements are not limited by these terms. If it is described that an element is "connected", "coupled" or "connected" to another element, it must be understood that the element can be connected or connected directly to another element or that another element can be interposed between them. Moreover, the phrase "having a specific configuration" relative to the invention means that it does not exclude any configuration other than the specific configuration but that any other additional configuration may be included in the embodiments of the invention or in the technical scope of the invention. Fig. 1 is a diagram schematically illustrating the insertion of auxiliary data into a main data frame to jointly transmit main data and auxiliary data. Auxiliary data such as a transmission identifier (ID) or emergency broadcast are additional data in addition to the main data. As shown in Fig. 1, auxiliary data 110 is inserted into a main data frame 120 having a length k and is transmitted with the main data. The auxiliary data has a low speed and a low capacity and is transmitted with a long code length L and a low transmission power P. At this time, the auxiliary data are inserted in addition to the main data and constitute interference with the data. data when a receiving terminal detects the main data. As a result, the detection capacity of the main data of the receiving terminal is reduced. Therefore, when a satisfactory capacity margin is guaranteed for the receiving terminal to detect the main data, the auxiliary data can be efficiently used without interference at the time of the detection of the main data. The invention relates to a method for the stable transmission of additional data at a high speed by giving a diversity gain or a sufficient capacity margin to the main data using many diversity techniques. Multiple diversity techniques using multiple antennas, such as space-time block coding (STBC), delay diversity (DD), cyclic delay diversity (CDD) and space-frequency block coding (SFBC) ), can be used in the invention. The diversity techniques described in this memo include various methods of improving the data transmission capability using one or more antennas, such as spatial multiplexing, cooperative transmission between macro base stations, a plurality of antennas. cooperative transmission between a macro base station and a micro base station, and a cooperative transmission using two or more transmitters. Multiple antennas have multiple base stations in the case of cooperative transmission using two or more base stations or two or more transmitters. For example, in the case of cooperative transmission between macro base stations, the multiple antennas can be realized by the macro base stations. In case of cooperative transmission between a macro base station and a micro base station, the multiple antennas can be realized by the macro base station and the micro station. Figure 2 is a diagram schematically illustrating the transmission of data from a transmitting terminal using multiple antennas. A signal sent from an S / P (serial-parallel) unit 210 is coded and modulated by a coding and modulation unit 220. The signal outputted from the coding and modulation unit 220 is sent to a unit. transmission unit 240 via a diversity signal processing unit 230. The transmission unit 240 transmits the signal using multiple antennas 250. Before sending the signal to the multiple antennas, the signal processing unit Diversity 230 executes processes necessary to provide diversity gain to a signal to be transmitted, such as signal assignment to multiple antennas and execution of a precoding operation. In this memo for purposes of practical explanation, such processes are defined as a diversity coding process. Fig. 3 is a diagram schematically illustrating an example in which transmitters in a broadcast system perform cooperative transmission to obtain diversity gain.

When two transmitters perform specific diversity coding processes, the receivers may obtain the diversity gain of the part in which two transmitters intersect each other. The use of several emitters is described here, but the invention is not limited to this example. It is the same in the case where several base stations perform the cooperative transmission. Fig. 4 is a diagram schematically illustrating an example in which a macro base station and a micro station located in a cell of the macro base station perform the cooperative transmission to obtain a diversity gain. The transmission power of the macro base station is strong and the transmission power of the micro base station is low. The macro base station and the micro base station may perform the mutually cooperative diversity encoding process so that receiving terminals obtain the diversity gain.

In this way, the use of various types of diversity techniques makes it possible to obtain a diversity gain in order to greatly increase the detection capability of the received signal. Fig. 5 is a diagram illustrating the comparison of bit error rate (BER) when using a space-time block coding (STBC) process with cases using a single antenna. As can be seen in the drawing, when space-time block coding is applied, the transmission capacity is greatly improved compared with the case where data is transmitted using a single antenna without using coding. of space-time blocks. For example, it can be noticed that the capacity is improved by about 10 dB or more with a BER of 10-3. This is an example of the capacity margin involved in transmitting a main data signal, which is mentioned in this memo. The space-time block coding illustrated in FIG. 5 is an example of the diversity techniques. When other diversity techniques are employed, the transmission capacity can also be improved in a similar manner. In this way, it is possible to achieve stable data transmission at a high rate by employing diversity techniques using multiple antennas. In other words, when the transmission capacity of the main data is improved by the use of diversity techniques, the margin of the transmission capacity can be used to achieve efficient transmission of the additional data. Fig. 6 is a block diagram schematically illustrating the configuration of a data signal transmission device or system according to an embodiment of the invention. A first coding and modulating unit 610 encodes and modulates a main data signal and sends the resulting signal to a first diversity processing unit 620. A second coding and modulation unit 630 encodes and modulates an auxiliary data signal and sends the resulting signal to a second diversity processing unit 640.

The first diversity processing unit 620 and the second diversity processing unit 640 perform a diversity coding process on the coded and modulated data signals. Here, according to the description given above, the diversity coding process comprises processes, necessary to give a diversity gain to the signals to be transmitted, such as an assignment of the signals to the multiple antennas and an execution of a precoding operation , before sending the signals to multiple antennas.

The main data signal and the auxiliary data signal having been subjected to the diversity coding process are sent to the signal coupling units 660 corresponding to the allocated antennas. The signal coupling units 650 perform processes necessary to transmit the main data signal together with the auxiliary data signal via the corresponding antennas, such as a coupling of the two data signals or an insertion of the auxiliary data signal into the data signal. a frame of the main data signal.

The main data signal and the auxiliary data signal sent from the signal coupling units 650 to the transceiver units 660 are transmitted via the assigned antennas among the antennas 670 constituting the multiple antennas.

The following will be described in detail with reference to the accompanying drawings, a method for improving the transmission capacity of an auxiliary data signal to be transmitted together with a main data signal whose transmission capacity has been improved to using diversity techniques.

Auxiliary data signal transmission power control (Improved auxiliary data detection capability) The transmission power of an auxiliary data signal can be increased with respect to the improvement of the transmission capacity of the auxiliary data signal. a main data signal.

When the auxiliary data signal is inserted into the frame of the main data signal and is transmitted with it, the auxiliary data signal can be inserted with an increased transmission power. Therefore, in order to avoid interference with the main data signal, the transmission power necessary to satisfactorily guarantee the transmission capacity of the auxiliary data signal can be supplied to the auxiliary data signal without inserting the signal. auxiliary data having low power in the main data signal. Since, as shown in Figure 5, the transmission capacity of the main data signal is increased by using the diversity techniques, it can be said that one acquires, at the same time, the capacity margin. Therefore, according to the description given above, it is possible to provide the auxiliary data signal with the improved power through the augmented capacity by employing the diversity techniques.

The auxiliary data signal with high power can be transmitted and received with better stability because the detection capability by a receiving terminal is improved. Since the auxiliary data signal having a high power can be inserted into the frame of the main data signal or can be transmitted together with the main data signal, it is possible to perform a strong auto-correlation. Therefore, it is possible to set the code length of the auxiliary data signal to a small value. Since more auxiliary data codes can be inserted into a transmission frame of a system and more auxiliary data codes can be transmitted with this frame, it follows that it is possible to execute a data communication at a high speed.

Fig. 7 is a diagram schematically illustrating a method of inserting auxiliary data signals 710-1, ..., 710-N in 720-1 and 720-N frames with which main data signals are transmitted according to an embodiment of the invention. The length L and the transmission power P of an auxiliary data signal can be varied in various ways depending on the quality of service (QoS) for the transmission system to which the invention is applied. The transmission power P of the auxiliary data signal can be increased according to the diversity gain given to the main data signal. It will be assumed that the transmission power supplied to the auxiliary data signal is P when the main data signal and the auxiliary data signal are transmitted with a single antenna. Then, the transmission power XP, weighted with a weight X, can be given to the auxiliary data signal to be transmitted according to the invention. At this time, it is possible to increase the transmission capacity of the auxiliary data signal by improving the weight X applied to the transmission power of the auxiliary data signal when the diversity gain obtained by the main data signal increases. The number of codes of the auxiliary data signals can be increased according to the diversity gain obtained by the main data signal. According to the description given above, since higher transmission power can be provided to the auxiliary data signal when the diversity gain obtained by the main data signal increases, it is possible to reduce the length of the signal code. auxiliary data and thus transmit more codes.

Transmission of Different Auxiliary Data Signals to Antennas (High Data Rate Guarantee) A master data signal and an ancillary data signal are transmitted together in the same transmission frame. Therefore, as the diversity gain obtained by the main data signal increases, the diversity gain obtained by the auxiliary data signal can also increase. Different auxiliary data signals can be transmitted using multiple antennas depending on the capacity margin obtained by the diversity gain. For example, depending on the capacitance margin obtained by the diversity gain, it may be considered that specific ancillary data signals are inserted in frames of main data signals to be transmitted via certain antennas of the antennas constituting the multiple antennas (y included in the case where a multiple antenna system comprises a plurality of base stations or transmitters) and are transmitted via the antennas, and other specific auxiliary data signals are inserted into frames of 18 main data signals to be transmitted. via other antennas and are transmitted via the antennas. It can also be taken into consideration that different auxiliary data signals are inserted into frames of main data signals and are transmitted via different transmission antennas constituting the multiple antennas (including the case in which the multiple antenna system comprises a plurality of stations). basic or multiple transmitters). At this time, the transmission power supplied to the auxiliary data signals may be low or may be strong as described above. In this way, the transmission speed of the auxiliary data signals can be guaranteed by the multiple of the number of antennas or transmitters. Therefore, it is possible to transmit auxiliary data at a high speed. According to this method, the auxiliary data signals can be assigned to specific antennas or transmitters or base stations and can be transmitted without transmitting the auxiliary data signals via all the transmission antennas. Therefore, it is possible to satisfy the quality of service of the transmission system as well as to acquire a high transmission rate for the auxiliary data. Fig. 8 is a diagram schematically illustrating a method of inserting auxiliary data signals 810-1, ..., and 810-N into frames 820-1, ..., 820-N with which data signals The main ones are transmitted in the system to which the invention is applied. Auxiliary data signals or some auxiliary data signals, inserted into frames 820-1, ..., and 820-N having a length k with which the main data signals are transmitted, are different from each other. In this case, the transmission power and the code length of the auxiliary data can be set differently based on the diversity gain or quality of service that is acquired by the transmission system.

Selecting the transmission channel based on the feedback information (Transmitting and receiving stabilization) Auxiliary data can be assigned to the antennas or base stations corresponding to the transmission channels having a good channel status and can be transmitted based on the transmission channel information transmitted by a return channel from a receiving terminal. Information on antennas or transmitters or base stations corresponding to the transmission channels of good quality can be received via the return channel from the receiving terminal. Therefore, a transmitting terminal can transmit the auxiliary data through only antennas or transmitters or base stations having a good channel state. As a result, transmission and reception can be stabilized and the influence on the main data signals can be minimized. Fig. 9 is a diagram schematically illustrating a method of inserting auxiliary data signals into frames of main data signals in the system to which the invention is applied. Here, it has been assumed that it has been determined that the quality of the 1st transmission channel and the 1st transmission channel satisfies the requirements for the system on the basis of the channel status information transmitted by a return channel 940 from of a receiver terminal 930. A transmitting terminal can insert auxiliary data signals 910-i and 910-j into frames 9201 and 920-j of main data signals to be transmitted via the antennas corresponding to the 1st transmission channel and the jth transmission channel and transmit the resulting signals based on the channel status information. Fig. 10 is a diagram schematically illustrating another method of inserting auxiliary data signals into frames of main data signals in the system to which the invention is applied. A transmitting terminal acquires main data signals and auxiliary data signals to be transmitted (S1010). At this time, the auxiliary data signals are auxiliary data such as TXID or emergency broadcast data to be transmitted together with the main data signals. The main data signals and the acquired auxiliary data signals are encoded and modulated (S1020). The main data signals and the auxiliary data signals may be coded and modulated according to various methods depending on the characteristics or structure of a transceiver system.

The main data signals and the auxiliary data signals are subjected to a diversity coding process (S1030). The diversity encoding process includes processes necessary for the signals to obtain a diversity gain, such as assigning the resulting diversity data signals to multiple antennas and performing a precoding operation. The main data signals and auxiliary data signals having been subjected to the diversity coding process are coupled (S1040). Here, as to the coupling of the main data signals and the auxiliary data signals, it is a process of processing the main data signals and / or the auxiliary data signals which makes it possible to transmit them together with the data signals. main data. For example, the auxiliary data signals may be inserted into the frames with which the main data signals are transmitted.

The main data signals and the auxiliary data signals are transmitted by multiple antennas 22 (S1050). At this time, the main data signals to be transmitted by the multiple antennas can obtain a large number of diversity gains according to the diversity techniques employed.

Since the auxiliary data signals are transmitted together with the main data signals, the auxiliary data signals can obtain the diversity gain, similar to the main data signals.

According to the description given above, various auxiliary data signals can be acquired during the acquisition step of the data signals (S1010) in order to transmit different auxiliary data signals as a function of the transmitting antennas.

The transmission power or the code length of the auxiliary data signals can be set during the step of encoding and modulating the acquired signals (S1020), during the step of executing an encoding process of diversity (S1030) and / or during the step of coupling the data signals (S1040). Although methods described below consist of a series of steps or blocks with a reference to flowcharts in the aforementioned system, the invention is not limited to this sequence of steps, but some step may be executed at a different time in another step or at the same time as another step. It will be appreciated by those skilled in the art that the steps illustrated in the flowcharts are not exclusive, but may include another step, or that one or more steps in the flowcharts may be omitted without affecting the scope of the invention. The aforementioned embodiments may include various modifications. It is not possible to describe all possible combinations of modifications, but one skilled in the art will understand that other combinations may be possible. Therefore, the invention is not limited to the embodiments described above and presented, from which we can provide other modes and other embodiments, without departing from the scope of the invention. .

Claims (14)

REVENDICATIONS1. A method of transmitting data signals using multiple antennas, comprising: performing a diversity process on a first encoded and modulated data signal; performing a diversity process on a second coded and modulated data signal; coupling said first signal with said second signal, the first data signal having been subjected to the diversity process and the second data signal having been subjected to the diversity process; and transmitting the first and second coupled data signals via the multiple antennas (250, 670), characterized in that the diversity process comprises a process of assigning the first data signal and the second data signal to the antennas of the multiple antennas (250, 670) in order to have diversity. A method of transmitting data signals according to claim 1, characterized in that the transmission power of the second data signal is increased on the basis of a diversity gain of the first data signal. A method of transmitting data signals according to claim 2, characterized in that a length of the code of the second data signal is decreased on the basis of an increased value of the transmission power. A method of transmitting data signals according to claim 1, characterized in that the transmission power of the second data signal is increased on the basis of the quality of service of a transmission channel. A method of transmitting data signals according to claim 1, characterized in that the second data signal comprises a plurality of different auxiliary data signals, and in that the plurality of auxiliary data signals are respectively allocated to the data signals. antennas of multiple antennas (250, 670), by using the diversity process on the second data signal. A method of transmitting data signals according to claim 5, characterized in that at least one of the plurality of different auxiliary data signals is assigned to each antenna of the multiple antennas (250, 670). The method of transmitting data signals according to claim 5, characterized in that the number of different auxiliary data signals is increased as a function of the diversity gain of the first data signal. 8. A data signal transmission method according to claim 5, characterized in that the transmission power is set to be different between the different auxiliary data signals. The method of transmitting data signals according to claim 1, further comprising receiving feedback information on a state of a transmission channel through which the first data signal and the second data signal are transmitted. transmitted, characterized in that only the second data signal assigned to the antennas having a good channel state of the second data signal having been subjected to the diversity process is coupled and transmitted with the corresponding first data signal among the first signal of data that has been submitted to the diversity process. A method of transmitting data signals according to claim 1, characterized in that the diversity process used to transmit the first data signal and the second data signal is one of a space-time block (STBC) coding process. , a delay diversity (DD), a cyclic delay diversity (CDD), a space-frequency block coding (SFBC), a spatial multiplexing, a cooperative transmission between macro base stations, a cooperative transmission between a base station macro and a micro base station and a cooperative transmission between transmitters. A data signal transmitting apparatus comprising: a first diversity processing unit (620) which executes a diversity process on a first coded and modulated data signal; a second diversity processing unit (640) that performs a diversity process on a second coded and modulated data signal; A plurality of signal coupling units (650) which couple signals sent by the first diversity processing unit 27 (620) and the second diversity processing unit (640); and a plurality of transceiver units (660) which receive signals from the signal coupling units (650) and send the signals to the corresponding antennas among the multiple antennas (250, 670) constituting a multiple antenna system characterized in that the diversity process comprises a process of assigning the first data signal and the second data signal to the antennas of the multiple antennas (250, 670) in order to have the diversity, and in that the plurality of The signal coupling units (650) and the plurality of transmit / receive units (660) uniquely correspond to the antennas of the multiple antenna system. A data signal transmission device according to claim 11, characterized in that the transmission power of the second data signal is increased on the basis of a diversity gain of the first data signal. Data signal transmission device according to claim 11, characterized in that the second data signal comprises a plurality of different auxiliary data signals (710-N), and in that the second diversity processing unit ( 640) executes the diversity process on the respective respective auxiliary data signals. 28 Data signal transmission device according to claim 11, characterized in that each transmission-reception unit (660) receives feedback information on a state of a transmission channel through which the first signal of data and the second data signal are transmitted, and in that the signal coupling units (650) couple only the second data signal assigned to the antenna having a good channel state from the second data signal having been subject to the diversity process, the first corresponding data signal from the first data signal having been subjected to the diversity process on the basis of the feedback information, and sending the coupled signal to the transceiver unit (660) corresponding to the antenna having a good channel state.