TWI444018B - Method for transmitting control signal using efficient multiplexing - Google Patents

Description

Method of transmitting control signals using efficient multiplexing

The present invention relates to a method for transmitting control signals in a multi-carrier mobile communication system, and more particularly to a method for transmitting control signals. Although the present invention has a wide range of applicability, it is particularly suitable for reliably transmitting control signals by efficiently multiplexing multiple 1-bit control signals in uplink/downlink transmission.

Generally, in a multi-carrier mobile communication system, a base station performs transmission of a downlink data packet to a plurality of user equipments (UEs) belonging to a unit or belonging to each of a plurality of units. At the same time, a plurality of user equipments may exist in one unit. Since each user equipment cannot know how the data packet will be transmitted to itself in a specified format, when the base station transmits the downlink data packet to the specific user equipment, the base station should transmit, for example, the following. Necessary information: user equipment identity certificate (will receive the corresponding information packet), time-frequency domain carrying the data packet, data transmission format including a coding rate, a modulation method and the like, HARQ related information and The downlink link is used to transmit similar information for each downlink data packet.

Conversely, in order for the user equipment to be able to transmit data packets at the uplink, the base station shall transmit the necessary information such as the identity of the user equipment (which may be allowed to transmit data packets), and allow the user equipment to transmit the data packet. The uplink time-frequency domain of the data packet, the data transmission format including a coding rate, a modulation method and the like, the HARQ related information, and the similar information used in the uplink link to transmit each uplink data packet.

When transmitting the uplink data packet, the base station shall transmit an acknowledgement/non-acknowledgement (ACK/NACK) message to each of the uplink nodes that have been transmitted by the user equipment to the corresponding user equipment. . On the other hand, when transmitting the downlink data packet, each user equipment transmits information about the success or failure of reception of each data packet that has been transmitted by the base station through the ACK/NACK information in the uplink.

In order to maintain the uplink transmission/reception power of each user equipment at an appropriate level, the base station should transmit power control data to each user equipment in the uplink.

Among the control signals described above, the ACK/NACK signal, the power control signal or the like is mainly used to indicate the corresponding information by using only one bit, and thus may be referred to as a "1-bit control signal".

In order to operate and manage the system effectively, it is necessary to multiplex the uplink/downlink control signals to carry the control information described above; in particular, it can effectively carry 1-bit control with data packets in a time-frequency resource. Signals and other signals.

As with the multiplex processing method generally used in multi-carrier mobile communication systems, the time division multiple access (TDMA) method multiplexes multiple signals by cutting them in the time domain. The frequency division multiple access (FDMA) method is to multiplex the signals by multiplexing a plurality of signals in the frequency domain; the code division multiple access (code division multiple access) The CDMA) method uses multiplexed codes or virtual orthogonal codes (or other similarly available methods) to multiplex the signals over a specified time-frequency domain.

However, when the 1-bit control signal is processed by using only the TDMA and/or FDMA methods, since the transmission power of each control signal is greatly different, the neighboring cells may have different influences in the time domain and/or the frequency domain. .

For example, especially when a random unit multiplexes ACK/NACK signals of different user equipments by TDMA or FDMA in a single TTI, if the ACK/NACK signal transmission power of each user equipment is greatly different, the units are added to The large amount of interference on adjacent neighboring units may vary greatly in the time domain or frequency domain. Moreover, such conditions may adversely affect the effective implementation of downlink data packet arrangements or time-frequency-energy dispersion in a cellular environment.

In addition, when a control signal such as an ACK/NACK signal of a transmission end fails to transmit in the downlink/uplink channel, there is a problem of reliability in transmitting the corresponding signal.

In accordance with the foregoing description, the present invention provides a method for transmitting control signals within a multi-carrier mobile communication system that substantially solves one or more problems due to the limitations and disadvantages of the related prior art.

The object of the present invention is to provide a method for efficiently transmitting a plurality of control signals, whereby the method can effectively perform multiplex processing to minimize mutual interference of cells in the control signal transmission, thereby reliably transmitting a specific one. Control signal at the transmitting end.

The additional features and advantages of the invention are set forth in the description which follows, The objectives and other advantages of the invention will be realized and attained by the <RTIgt;

In order to achieve the foregoing and other advantages and in accordance with the purpose of the present invention, in accordance with the specific embodiments and the broad description of the specification, a method of transmitting control signals in accordance with the present invention includes a method of code division multiplexing access (CDMA) The multiplexer processes a plurality of 1-bit control signals in a specified time-frequency domain, repeats the multiplexed process control signals in different frequency domains, and transmits the repeated control signals.

In order to achieve the foregoing and other advantages and in accordance with the purpose of the present invention, in accordance with the specific embodiments and the broad description of the specification, a method of transmitting control signals in accordance with the present invention includes a method of code division multiplexing access (CDMA) Multiplex processing a plurality of 1-bit control signals in a specified time-frequency domain, and transmitting the multiplexed control signals, wherein the plurality of 1-bit control signals comprise a plurality of 1-bits of a particular transmission end Control signal.

Preferably, the specified time-frequency domain comprises a time-frequency domain within a band of 1 OFDM symbols.

Preferably, in a case where a time domain for transmitting the control signal includes a single OFDM symbol band, the repetitive action is to repeat the multiplex processing control signals in the single OFDM symbol band to Implemented in different frequency domains.

Preferably, in a case where a time domain for transmitting the control signal includes a plurality of OFDM symbol bands, the repeating operation repeats the multiplexed control signal in different OFDM symbol bands from each other. Implemented in different frequency domains.

Preferably, in the multiplexing process, the plurality of 1-bit control signals are distinguished by an orthogonal or virtual orthogonal code for multiplexing each of the 1-bit control signals. .

Preferably, the plurality of 1-bit control signals are respectively distinguished by different orthogonal phase components, and are thereby modulated; and wherein, in the multiplexing processing, the plurality of 1-bits The control signals are further distinguished by the different quadrature phase components used for modulation.

Preferably, the specified time-frequency domain comprises a plurality of time-frequency domains. In multiplex processing, additional multiplex processing is implemented by at least one of Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). Moreover, the plurality of 1-bit control signals of the particular transmission end are multiplexed by being distributed in the plurality of time-frequency domains.

Preferably, the 1-bit control signals of different transmission ends are separately processed by the code division multiplexing access method in the plurality of time-frequency domains. In this case, the plurality of 1-bit control signals of the particular transmission end are multiplexed by different orthogonal or virtual orthogonal codes.

Moreover, the orthogonal or virtual orthogonal code comprises a sequence of codes whose length corresponds to the size of the plurality of time-frequency domains.

In addition, the 1-bit control signal may include an ACK/NACK signal or a power control signal. Moreover, the 1-bit control signal can be transmitted in an uplink or downlink link.

It is to be understood that the foregoing general description

According to an embodiment of the present invention, the CDMA method is mainly used when multiplexing a plurality of 1-bit control signals. Additionally, a plurality of control signals for a particular user equipment may be transmitted via different orthogonal or virtual orthogonal codes, respectively. Therefore, the reliability of the corresponding control signal transmission can be improved.

Moreover, the FDMA and/or TDMA method can be implemented to transmit a 1-bit control signal, and the distributed control mode can be used to transmit a plurality of control signals of a fixed user equipment on each time-frequency domain. The amount of multiplexed processing of signals in the same bandwidth and/or coherence time.

In addition, in the case of transmitting a 1-bit control signal via a plurality of time-frequency domains, by explicitly indicating the use of an orthogonal code (the orthogonal code is based on the entire time-frequency domain size rather than the individual time-frequency domain Size for transmission), which increases the amount of control signals that can be transmitted simultaneously.

In addition, in the case where a plurality of OFDM symbols are used to transmit a 1-bit control signal, a 1-bit control signal modulated by the CDMA method is transmitted over different OFDM symbol regions through different frequency domains, and resources are available. The transmission is effectively performed under the characteristics of efficiency and diversity gain. At the same time, the power configuration can be made more flexible in each OFDM symbol region.

DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the preferred embodiments embodiments

In general, the base station transmits an ACK/NACK signal indicating that the data packet transmitted by each user equipment in a unit is successfully received or received, or a control signal is in the downlink link. Plays a role similar to the ACK/NACK signal corresponding to the user equipment. In this way, when a plurality of user equipments can transmit uplink data packet in a single TTI, the base station can simultaneously transmit ACK/NACK signals to the plurality of user equipments in a single TTI.

In addition, the base station multiplexes a plurality of power control signals to control the transmission power of the uplink data of the plurality of user equipments in a single TTI, and then transmits the multiplexed processing signals to each user equipment.

Therefore, in accordance with an embodiment of the present invention, in order to efficiently transmit a plurality of 1-bit control signals, the embodiment provides a method for borrowing part of the time-frequency domain of a next transmission band of a multi-carrier system. A plurality of 1-bit control signals are transmitted by the CDMA method. Moreover, this manner will be described with reference to a detailed embodiment.

Meanwhile, the description of an embodiment of the present invention relates to the case where the 1-bit control signal is an ACK/NACK signal. In the method of transmitting a control signal according to an embodiment of the present invention, the 1-bit control signal does not have to be an ACK/NACK signal. Moreover, it will be apparent to those skilled in the art that the present invention includes a random 1-bit control signal in a format in which a plurality of signals are transmitted within 1 TTI.

1 is an explanatory diagram of a multiplex transmission method according to an embodiment of the present invention, which uses CDMA technology to transmit an ACK/NACK signal.

Referring to Figure 1, in accordance with an embodiment of the present invention, a base station maintains a particular time-frequency domain within a TTI for use as a transport ACK/NACK. In addition, the ACK/NACK signals of different user equipments are distinguished by adding additional orthogonal or virtual orthogonal codes to a time-frequency domain.

In this case, "orthogonal code" or "virtual orthogonal code" is used to process the signal in the CDMA method and can be used as an indicator to indicate that the correlation is zero or the value is less than a specified threshold. The situation.

According to a preferred embodiment of the present invention, when transmission is performed by a modulation technique in which components are phase-orthogonal to each other by a method such as QPSK, a plurality of ACK/NACK signals can be composed via different orthogonal phase components. Also distinguish.

In the embodiment shown in FIG. 1, when the ACK/NACK signal is transmitted by including 12 subcarriers in a single TTI across a time-frequency domain of 6 OFDM symbols, a chip length of 72 can be used ( An orthogonal code of =6x12) to transmit an ACK/NACK signal. Therefore, 72 different orthogonal signals can be transmitted simultaneously. However, many of the simultaneously transmittable orthogonal signals may vary with the type of orthogonal/virtual orthogonal code used.

In the case where the embodiment shown in Fig. 1 uses QPSK as the modulation method, a quadrature quadrature phase can be used. Therefore, a total of 72 different orthogonal signals of 72 orthogonal signals can be transmitted.

At the same time, the ACK/NACK signal of the single user equipment can be transmitted via a single orthogonal signal in the orthogonal signal generated by the foregoing method. However, an embodiment of the present invention provides for ACK/NACK signals of a single user equipment in the case where a single ACK/NACK signal carries more than one bit of information or that a single user equipment transmits a plurality of data packets in a single TTI. The set is transmitted through a plurality of orthogonal signals.

As an embodiment of the present invention as described above, there is an advantage in multiplexing the ACK/NACK signal by the CDMA method in the downlink, which is an ACK on the downlink link in a time-frequency domain of a single TTI. The large amount of interference generated by the /NACK signal can be maintained at a relatively equal amount.

In particular, in the case where a random unit multiplexes ACK/NACK signals of different user equipments by TDMA or FDMA in a single TTI, as mentioned in the foregoing, if the ACK/NACK signals of individual user equipments transmit power If the differences are large, the amount of interference that the units add to the corresponding neighboring units may be greatly different in the time domain or the frequency domain. Moreover, such conditions may adversely affect the effective implementation of downlink data packet arrangements or other time-frequency-energy dispersion in a cellular environment. However, in the case where the ACK/NACK signal is processed by the CDMA method in a specific embodiment of the present invention, ACK/NACK of all user equipments is transmitted even when different ACK/NACK signal transmission powers are allocated to different user equipments. The signals are added together in the same time-frequency domain of a single TTI and then transmitted. Therefore, the variation of the transmitted power over a time-frequency domain can be minimized.

According to an embodiment of the present invention, in a case where a plurality of ACK/NACK signals (the signals are transmitted by a single user equipment or transmitted for transmitting a single user equipment data) are transmitted through a plurality of orthogonal signals, The reliability of transmitting the ACK/NACK signal to the corresponding user equipment can be increased.

In addition, the downlink link transmission principle of the ACK/NACK signal described above can be applied to the uplink link transmission in the same manner.

Meanwhile, when the ACK/NACK signal is processed by the CDMA method, as mentioned in the foregoing description, the orthogonality between different ACK/NACK signals processed by the CDMA method is only when the downlink node radio channel response feature The orthogonality can be maintained when there is not much change in the time-frequency domain carrying the ACK/NACK signal. Therefore, satisfactory reception performance can still be obtained without using a special reception algorithm such as a channel equalizer at the receiving end. Preferably, the ACK/NACK signal is processed by CDMA in a time-frequency domain, and a radio channel response is not changed too much in the time-frequency domain, that is, in a co-ordinated time and a co-modulation bandwidth. Inside.

According to a detailed embodiment of the present invention, FDMA or TDMA multiplexing processing can be simultaneously used to implement transmission. CDMA/multiplex processing is used to process ACK/NACK signals to reduce CDMA/MIMO processing in a coherent range. A time-frequency domain of the signal within which a radio channel response feature has not changed too much. This will be explained below.

FIG. 2 is a diagram illustrating a method of transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method performs multiplex processing of ACK/NACK signals by using both CDMA and FDMA methods.

Referring to Figure 2, different ACK/NACK signals can be transmitted in time-frequency domains separated from each other on the two frequency axes. Moreover, different ACK/NACK signals can be multiplexed in the CDMA method in each time-frequency domain. In this case, according to an embodiment of the present invention, when the ACK/NACK signal is transmitted through two frequency domains, it can be observed that the width of each frequency domain is set to 6 subcarrier bands, and the width thereof is smaller than 12 subcarrier bands.

In particular, in the embodiment shown in FIG. 2, since the two time-frequency domains all contain 6 OFDM symbols and 12 subcarriers, 36 (=6x6) orthogonal signals can be transmitted by the CDMA method. Since the two time-frequency domain is used within a single TTI, 72 (= 36x2) orthogonal signals can be transmitted.

In the case of QPSK modulation, since the two orthogonal phases can be used to additionally distinguish the ACK/NACK signals, different orthogonal signals equivalent to twice the amount of the 72 orthogonal signals can be transmitted.

FIG. 3 is a diagram illustrating a method of transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method performs multiplex processing of ACK/NACK signals by simultaneously using CDMA, TDMA, and FDMA methods. In particular, FIG. 3 shows an embodiment in which multiplex processing of ACK/NACK signals is performed by simultaneous CDMA, FDMA, and TDMA methods.

Referring to Figure 3, different ACK/NACK signals can be transmitted in a time-frequency domain where the four channels are less changed. In addition, different ACK/NACK signals can be multiplexed in each time-frequency domain using the CDMA method.

In particular, in the embodiment shown in FIG. 3, since each time-frequency domain includes three OFDM symbols and six subcarriers, 18 (=3x6) ACK/ can be transmitted in each time-frequency domain by the CDMA method. NACK signal. Since the four time-frequency domain is used in a single TTI, a 72 (= 18x4) ACK/NACK signal can also be transmitted. Since the two quadrature phases can be used as QPSK transmissions, an ACK/NACK signal equivalent to twice the amount of the different ACK/NACK signals can be transmitted.

The foregoing ACK/NACK signal multiplexing processing method shown in FIG. 2 or FIG. 3 is for transmitting different ACK/NACK signals in each time-frequency domain, which is more than the method shown in FIG. Have an advantage. In the method shown in Figure 1, each ACK/NACK signal can be transmitted in a time-frequency domain with radio channel response characteristics that do not change too much; however, in the time-frequency domain as an ACK/NACK signal In the case where the quality of the radio channel of the designated user equipment is poor, the ACK/NACK reception performance of the corresponding user equipment is greatly reduced.

Accordingly, an embodiment of the present invention provides that a particular user equipment ACK/NACK signal within a single TTI can be transmitted across a time-frequency domain that is remote from a plurality of time-frequency axes. In addition, an embodiment of the present invention also proposes a method for obtaining time-frequency diversity gain of ACK/NACK signal reception at the receiving end, which is multiplexed in each time-frequency domain by the CDMA method. Handle ACK/NACK signals from different user equipments.

FIG. 4 is a schematic diagram of a method for transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method performs multiplex processing of ACK/NACK signals by using both CDMA and FDMA methods; wherein a plurality of ACK/ A plurality of ACK/NACK signals transmitted by a specific transmission end in the NACK signal are transmitted through a plurality of frequency domains.

Referring to FIG. 4, a receiving end obtains a frequency diversity gain by transmitting ACK/NACK signals across two different frequency domains. In the embodiment shown in FIG. 4, the ACK/NACK signal is transmitted across the two time-frequency domains and different ACK/NACK signals are multiplexed in each time-frequency domain.

In particular, since each time-frequency domain includes six OFDM symbols and six subcarriers, 36 (=6x6) ACK/NACK signals can be multiplexed in each time-frequency domain by CDMA. Since the two quadrature phases can be used as QPSK transmissions, an ACK/NACK signal equivalent to twice the amount of the different ACK/NACK signals can be transmitted.

As mentioned in the foregoing description, orthogonal codes (adjusted according to the size of each time-frequency domain) are used in each time-frequency domain to process different ACK/NACK signals through different time-frequency domains. The ACK/NACK signal of a particular user equipment being transmitted may be multiplexed by the same orthogonal code used in the orthogonal code of each time-frequency domain.

However, an embodiment of the present invention proposes that an ACK/NACK signal of a particular user equipment transmitted via different time-frequency domains can be used by using different orthogonal codes used in each time-frequency domain. Multiple processing.

Therefore, when the ACK/NACK signal of a specific user equipment is multiplexed using different orthogonal codes in each time-frequency domain, the influence parameters and other ACK/NACK can be reduced by special orthogonality. Signals to avoid degradation of reception performance; a particular ACK/NACK signal with orthogonality reduction parameters is multiplexed in CDMA during a particular TTI. In addition, the method can be extended such that an ACK/NACK signal of a specific user equipment can be used in different time-frequency domains even if the ACK/NACK signal is transmitted via at least three time-frequency domains. Different orthogonal codes are used to transmit the ACK/NACK signal of the specific user equipment.

As shown in FIG. 4, when the ACK/NACK signal is transmitted through a plurality of time-frequency domains, a preferred embodiment of the present invention proposes a method for simultaneously transmitting more ACK/NACK signals; Specifically, an orthogonal code corresponding to the entire time-frequency domain size is specified, instead of specifically specifying an orthogonal code corresponding to each time-frequency domain size, and then a plurality of ACK/NACK signals are transmitted.

In particular, in the embodiment shown in FIG. 4, by obtaining an orthogonal code (6x12 of the chip length 72, according to the 6 OFDM symbol belonging to the two time-frequency domain and the 12 subcarriers, the two time-frequency domain system is used. In order to carry a plurality of ACK/NACK signals of a specific user equipment instead of the chip length 36 (according to 6 OFDM symbols and 6 subcarriers belonging to a single time-frequency domain), different signals may be used in the case of transmitting signals using QPSK technology. Quadrature phase to transmit 144 ACK/NACK signals simultaneously.

In this case, the problem that the orthogonality between the orthogonal codes is degraded due to the large difference in the radio channel responses of different time-frequency domains may be caused by the correlation feature of the intersection between the orthogonal codes. The ACK/NACK transmission powers different from each other are allocated to overcome this problem.

In particular, if the codes of low orthogonality in the orthogonal codes specifically mentioned above are grouped into groups to match the transmission power of orthogonal codes within a corresponding group, the above orthogonality problem can be solve.

FIG. 5 is a schematic diagram of a method for transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method performs multiplex processing of ACK/NACK signals by using CDMA, TDMA, and FDMA methods simultaneously; A plurality of ACK/NACK signals transmitted by a specific transmission end in the ACK/NACK signal will be transmitted through a plurality of frequency domains.

Figure 5 shows an embodiment in which the ACK/NACK signal of a particular user equipment is transmitted across two different time-frequency domains in such a way as to obtain a time-frequency diversity gain.

In particular, the ACK/NACK signals of the user equipments 1 to N/4 are transmitted via a time-frequency domain located in the upper left portion of FIG. 5 and a time-frequency domain located in the lower right portion of FIG. The ACK/NACK signals of the user equipment N/4+1 to N/2 are transmitted via a time-frequency domain located in the lower left portion of FIG. 5 and a time-frequency domain located in the upper right portion of FIG.

In particular, in the embodiment illustrated in Figure 5, the ACK/NACK signal for a particular user equipment is transmitted across the two time-frequency domains. The different ACK/NACK signals are then multiplexed in each time-frequency domain by the CDMA method.

In addition, the 18 ACK/NACK signal can be transmitted via an orthogonal code that spans three OFDM symbols and six corresponding sub-carrier lengths (= 3x6) in each time-frequency domain. Since the two quadrature phases can be used for QPSK transmission, a total of 36 different ACK/NACK signals equivalent to twice the amount of the aforementioned ACK/NACK signals can be transmitted.

In the embodiment shown in FIG. 5, an ACK/NACK signal transmitted by a specific user equipment via different time-frequency domains and other ACK/NACK signals using the same orthogonal code can be distinguished. However, the diversity gain can be obtained by processing ACK/NACK signals in each time-frequency domain using different orthogonal code multiplexing.

Furthermore, in the embodiment shown in FIG. 5, more ACK/NACK signals can be transmitted simultaneously, depending on the entire time-frequency domain size rather than the individual time-frequency domain size to specifically indicate the orthogonal code.

In particular, by specifically indicating the orthogonal code of the wafer length 72 composed of a total of six OFDM symbols and 12 subcarriers, instead of the orthogonal code of the wafer length 18 composed of three symbols and six subcarriers, it is possible to simultaneously transmit more Multiple ACK/NACK signals.

In the specific embodiments shown in the foregoing first to fifth embodiments, for example, a one-bit control signal such as an ACK/NACK signal is transmitted by being dispersed in a 3 or 6 OFDM symbol band by the CDMA method. However, an OFDM symbol band that can be used to transmit a 1-bit control signal, such as an ACK/NACK signal, can include at least one or more OFDM symbols.

In the 1-bit control signal (ACK/NACK signal) transmission method according to the foregoing specific embodiment of the present invention, the method for repeatedly transmitting ACK/NACK signals in a plurality of time-frequency domains to ensure transmission diversity gain The method can be diversified depending on the number of OFDM symbol bands that can be used. In the following description, a method will be described in which OFDM symbols are transmitted in accordance with a plurality of OFDM/NACK signals used to transmit ACK/NACK signals efficiently.

Figure 6 is a diagram illustrating a method of transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method uses an OFDM symbol band to transmit an ACK/NACK signal.

In detail, FIG. 6 shows that the four ACK/NACK signals are distributed in a 1 OFDM symbol band by a distribution factor (SF) 4, and then the ACK/NACK signals are multiplexed by CDMA. In Figure 6, a single interval represents a single subcarrier band. Further, A _ij denotes an ACK/NACK signal which is multiplexed by the CDMA method. In this embodiment, "i" represents an index of distributed and multiplexed processing signals, and "j" represents an index of the multiplexed processing ACK/NACK signal group. An ACK/NACK group represents a set of ACK/NACK signals that are transmitted by multiplex. In addition, a plurality of ACK/NACK groups may exist depending on the necessity of each system and the resource status. For clarity of illustration and description, Figure 6 assumes that there is only a single ACK/NACK group.

Since this embodiment assumes that only a single OFDM symbol is used to transmit an ACK/NACK signal, the diversity gain of the ACK/NACK signal transmission on the time axis cannot be obtained.

However, to obtain diversity gain on the frequency axis, ACK/NACK signals that are multiplexed on the frequency axis by the CDMA method can be repeatedly transmitted in different frequency domains.

Figure 6 shows an embodiment in which the ACK/NACK signal processed by the CDMA method is repeated four times in different frequency domains. In this case, four times the repeated signal is just an example of obtaining diversity. The number of signal repetitions varies depending on the channel status and resource status of the system. In Fig. 6, each of the ACK/NACK signals repeated four times has the same index (i, j) to emphasize that it is a repeated signal of the signal. However, each of the ACK/NACK signals that are repeated four times can be multiplexed by different orthogonal codes or the like, so in this case, the repeated signals can be different from each other. Signal. However, for ease of explanation, the difference in each repeated signal will be ignored in the full text.

Figure 6 deals with the case where a single OFDM symbol is used to transmit an ACKNACK signal. The use of a single OFDM symbol is merely for the purpose of illustrating one embodiment of the invention. Moreover, the present invention is also applicable to the case of using a plurality of OFDM symbols.

More specifically, in the case where ACK/NACK is transmitted via several OFDM symbols, repeating the signal on the time axis and repeating the signal on the frequency axis are equally implementable to obtain additional diversity and transmit antenna diversity.

In the following description, a case where a plurality of OFDM symbols are used to transmit an ACK/NACK signal will be explained.

In the case where the OFDM symbol amount is increased to transmit the ACK/NACK signal, when a single OFDM symbol is used to transmit the ACK/NACK signal, the ACK/NACK signal can be repeatedly used to match the added OFDM symbol. In this case, since the OFDM symbol used to transmit the ACK/NACK signal is increased, more signal power can be used to transmit the ACK/NACK signal. Therefore, an ACK/NACK signal can be transmitted to a wider area of a unit.

FIG. 7 is a diagram illustrating a method of transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method uses at least 2 OFDM symbol bands to transmit an ACK/NACK signal.

Fig. 7 shows an ACK/NACK signal transmission method which processes when a plurality of OFDM symbols for transmitting an ACK/NACK signal are increased to two, and the ACK/NACK signal has the same distribution factor as that of Fig. 6. In particular, FIG. 7 shows a structure when a single OFDM symbol is used to transmit an ACK/NACK signal as shown in FIG. 6, and this structure can be completely and repeatedly applied to a second OFDM symbol.

When transmitting using the foregoing structure, even when the number of symbols is increased, the number of ACK/NACK signals that can be transmitted is equivalent to the case of using a single OFDM symbol. This is because in the case where only a single OFDM symbol is used, when more OFDM symbols are used to transmit ACK/NACK signals that are only repeated on the frequency axis, by increasing the number of time-frequency repetitions, more Time-frequency resources are used to transmit the same number of ACK/NACK signals.

When the transmission is performed in this way, more power can be allocated to the ACK/NACK signal transmission, but resource waste may occur. In the case where there are more OFDM symbols used to transmit ACK/NACK signals to reduce resource waste, if the transmission is performed by increasing the number of repetitions of each OFDM symbol on the frequency axis, then a single OFDM symbol is used. The same time-frequency domain can be occupied. Therefore, resources can be utilized more efficiently.

FIG. 8 is a diagram illustrating a method of transmitting an ACK/NACK signal. According to an embodiment of the present invention, the method uses at least 2 OFDM symbol bands to transmit an ACK/NACK signal.

Figure 8 shows an embodiment in which resources are more efficiently utilized by increasing the number of repetitions of ACK/NACK signals on the frequency axis. In this example, the ACK/NACK signal is multiplexed by the CDMA method and is increased to two in the number of OFDM symbols used to transmit the ACK/NACK signal.

When the number of OFDM symbols used to transmit the ACK/NACK signal is increased, compared with the repetition of four times in FIG. 6, although the ACK/NACK signal is repeated twice, the quadruple time-frequency resource domain is used. The same is true for a single OFDM symbol.

Compared with the case where the same ACK/NACK signal structure is applied to the entire OFDM symbol to perform transmission as shown in FIG. 7, assuming that the same time-frequency resource is used, FIG. 8 shows that the transmission of the ACK/NACK signal may be doubled. Therefore, resources can be used more efficiently.

Compared with Fig. 7, since the number of time-frequency resource domains used to transmit ACK/NACK signals is increased, the signal power for transmitting ACK/NACK signals may become small. However, since the total ACK/NACK signal is transmitted across the time-frequency domain, the transmission power allocation per symbol may be more efficient than the case where only a single OFDM symbol is used to transmit the ACK/NACK signal.

Referring to Figure 8, when a plurality of OFDM symbol bands are used to transmit ACK/NACK signals, in accordance with a particular embodiment of the present invention, a particular ACK/NACK is transmitted via a different frequency domain within each OFDM symbol band. In the case of the signal method, power distribution can be more flexibly implemented to each ACK/NACK signal; thus, the power distribution flexibility is more than the method of transmitting ACK/NACK signals via different frequency domains within each OFDM symbol band. There are more advantages. This will be described in detail below with reference to FIG.

Fig. 9 is a diagram showing the principle in which the power distribution elasticity is increased in the case where the ACK/NACK signal is transmitted in the specific embodiment of Fig. 8.

In Fig. 9 (a) and (b), A ₁ , A ₂ , A ₃ and A ₄ respectively represent ACK/NACK signal groups transmitted by the CDMA method. In particular, Figure 9(a) shows a format in which ACK/NACK signals processed by CDMA multiplexing are transmitted by being repeated in different frequency domains within the same symbol band. And FIG. 9(b) shows a format in which ACK/NACK signals processed by CDMA multiplexing according to an embodiment of the present invention are transmitted by being repeated in different frequency domains in different OFDM symbol bands, respectively. .

In the case where the ACK/NACK signal is transmitted in the same manner as in FIG. 9(a), the total power allocated to the individual OFDM symbol band should be allocated by distributing the power to the two ACK/NACK signals. Conversely, in the case where the ACK/NACK signal is transmitted in the same manner as in FIG. 9(b), the total power allocated to the individual OFDM symbol band can be allocated by distributing the power to the four ACK/NACK signals. . Therefore, the elasticity of the electric power distribution can be improved and higher than the case of Fig. 9(a).

In other words, when the number of OFDM symbol bands available for transmitting ACK/NACK signals is complex, as in the specific embodiment of the present invention, in the case where ACK/NACK signals are transmitted via different frequency domains within different OFDM symbols, The power distribution flexibility is enhanced to diversify the power distribution of each user's ACK/NACK signal.

In the foregoing specific embodiment of the present invention, a distribution factor for multiplexing processing a plurality of ACK/NACK signals, a number of repetitions in the time-frequency domain, and the number of OFDM symbols used to transmit ACK/NACK signals, The present invention is merely illustrative of the embodiments, but other distribution factors, other repetition numbers, and various OFDM symbol numbers are applicable to the present invention.

In the foregoing embodiment of the invention in terms of time-frequency resources, only the case of using a single transmission antenna without using transmission antenna diversity is indicated. The invention may also be selected for use in the use of two transmit antenna diversity methods or four transmit antenna diversity methods.

It is apparent to those skilled in the art that the above described method for obtaining time-frequency diversity gain from ACK/NACK signal transmission can be used simultaneously with FDMA or TDMA and CDMA methods. One embodiment of the present invention multiplexes different ACK/NACK signals.

The multiplexed processing and transmission ACK/NACK signal method described above can also be applied to a method of multiplexing and transmitting a plurality of power control signals transmitted to different user equipments in a downlink. In particular, the downlink ACK/NACK signal and the downlink power control signal can be multiplexed and transmitted in the same time-frequency domain by the CDMA method.

In addition, the multiplex processing and the method of transmitting the ACK/NACK signal described above can also be applied to the transmission of the uplink ACK/NACK signal of the data packet, and the data packet is also transmitted in the downlink link.

In addition, if the number of OFDM symbols used to transmit ACK/NACK signals can vary within a particular system, it is preferable to reduce the number of ACK/NACK signal repetitions depending on the number of OFDM symbols used.

According to an embodiment of the present invention, when multiplexing a plurality of 1-bit control signals, a plurality of control signals of a specific user equipment may be via orthogonal or virtual orthogonal codes different from each other and mainly using a CDMA method. transmission. Thus, the present invention enhances the reliability of a corresponding control signal transmission.

In addition, the frequency and/or time can be obtained by simultaneously implementing the FDMA and/or TDMA method to transmit a 1-bit control signal and by distributing a plurality of control signals of a specific user equipment in each time-frequency domain. separation.

In addition, in the case of transmitting a 1-bit control signal via a plurality of time-frequency domains, by explicitly indicating the use of orthogonal codes (which are used for transmission, and depending on the entire time-frequency domain size rather than each time) Depending on the size of the frequency domain, the number of control signals that can be transmitted simultaneously can be increased.

In addition, in the case where a plurality of OFDM symbols are used to transmit a 1-bit control signal, the 1-bit control signal modulated by the CDMA method on different OFDM symbol regions is transmitted through different frequency domains. Improve transmission advantages in terms of resource efficiency and diversity gain. Moreover, a more flexible power distribution can be achieved in each OFDM symbol region.

Therefore, the control information transmission method according to one of the present invention is adapted to configure an application on a 3GPP LTE system. Furthermore, the control information transmission method according to one of the present invention can be applied to a random communication system, and the system and the 3GPP LTE system need to describe the control information transmission format in the time-frequency domain in the specification.

Herein, the invention has been described and illustrated with reference to the preferred embodiments. It will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope and spirit of the invention. Accordingly, the invention is intended to cover various modifications and alternatives

The accompanying drawings are included to provide a further understanding of the invention and a part of the description. The drawings illustrate the specific embodiments of the invention, and the description of the invention

In the figure: FIG. 1 is an explanatory diagram of a multiplex processing method, which transmits ACK/NACK signals by CDMA technology according to an embodiment of the present invention; FIG. 2 is an explanatory diagram of a transmission ACK/NACK method. According to an embodiment of the present invention, an ACK/NACK signal is transmitted by performing multiplex processing at both ends by using CDMA and FDMA technologies; and FIG. 3 is an explanatory diagram of a method for transmitting ACK/NACK, according to the method. One embodiment of the present invention transmits ACK/NACK signals by multiplexing processing at both ends by using CDMA, TDMA, and FDMA technologies; FIG. 4 is an explanatory diagram of a method for transmitting ACK/NACK, and the method is according to one of the present inventions. The specific embodiment transmits ACK/NACK signals by implementing multiplexing processing at both ends by CDMA and FDMA technologies. The plurality of ACK/NACK signals transmitted by a specific transmission end between the plurality of ACK/NACK signals are transmitted through a plurality of frequency domains; FIG. 5 is an explanatory diagram of a method for transmitting ACK/NACK, and the method is based on the method. One embodiment of the invention implements multiplex processing at both ends by CDMA, TDMA, and FDMA techniques to transmit ACK/NACK signals. The plurality of ACK/NACK signals transmitted by a specific transmission end between the plurality of ACK/NACK signals are transmitted through a plurality of frequency domains; FIG. 6 is an explanatory diagram of a transmission ACK/NACK method, and the method is based on the method. One embodiment of the invention uses an OFDM symbol region to transmit an ACK/NACK signal; FIG. 7 is a diagram of a method for transmitting an ACK/NACK method that uses at least 2 OFDM symbol regions to transmit an ACK in accordance with an embodiment of the present invention. /NACK signal; FIG. 8 is an explanatory diagram of a method for transmitting ACK/NACK, which uses at least 2 OFDM symbol regions to transmit ACK/NACK signals according to a preferred embodiment of the present invention; and FIG. 9 is a transmission ACK /NACK signal principle diagram, the principle is based on the specific embodiment of Figure 8 to increase the power distribution flexibility.

Claims (14)

A method for transmitting acknowledgment/non-acknowledgment (ACK/NACK) information by a base station, the method comprising the steps of: multiplexing multiple ACK/NACKs with different orthogonal codes Processing into an ACK/NACK group; and transmitting, in a transmission time interval (TTI) including a plurality of OFDM symbols, the ACK/NACK group by each of a predetermined number of multiple resource sets, Each of the sets of equal resources includes a predetermined number of subcarriers and an orthogonal frequency division multiplexing (OFDM) symbol, wherein the predetermined number of the plurality of resource sets are separated from each other along a frequency axis, and wherein The plurality of ACK/NACKs in the ACK/NACK group are distinguished from one another by the different orthogonal codes. The method of claim 1, wherein when the number of OFDM symbols used for ACK/NACK transmission in the TTI is one, the predetermined number of multiple resource sets are along a single frequency division multiplexing ( The frequency axes of the OFDM symbols are separated from one another. The method of claim 1, wherein when the number of the OFDM symbols used for ACK/NACK transmission in the TTI is two, The predetermined number of resource sets separated from each other by the frequency axis are alternated between two OFDM symbols. The method of claim 1, wherein the plurality of ACK/NACKs are further multiplexed by using phase components orthogonal to each other. The method of claim 4, wherein the plurality of ACK/NACKs in the ACK/NACK group are further distinguished by the phase components for the plurality of ACK/NACKs. The method of claim 4, wherein the maximum number of the plurality of ACK/NACKs transmitted using the predetermined number of the plurality of resource sets is a multiple of a predetermined number of the subcarriers, the sub A carrier system is included in each of the predetermined number of sets of resources. The method of any one of claims 1 to 6, wherein each of the different orthogonal codes has a length of "4", each of the predetermined number of resource sets comprising "4" subcarriers, and the maximum number of one of the plurality of ACK/NACKs multiplexed in the ACK/NACK group is a multiple of "4". A successful receipt/reception by a user equipment A method for acknowledging (ACK/NACK) information, the method comprising the steps of: receiving an ACK/NACK group through each of a predetermined number of resource sets in a Transmission Time Interval (TTI) comprising a plurality of OFDM symbols Group, the ACK/NACK group includes a plurality of ACK/NACKs using different orthogonal codes, each of the resource sets including a predetermined number of subcarriers and an orthogonal frequency division multiplexing (OFDM) symbol, where A predetermined number of the plurality of resource sets are separated from each other along a frequency axis, and wherein the plurality of ACK/NACKs in the ACK/NACK group are distinguished from one another by the different orthogonal codes. The method of claim 8, wherein when the number of OFDM symbols used for ACK/NACK transmission in the TTI is one, the predetermined number of multiple resource sets are along a single frequency division multiplexing (OFDM) The frequency axis of the symbol is separated from each other. The method of claim 8, wherein the predetermined number of the plurality of resource sets separated from each other along the frequency axis when the number of the OFDM symbols used for ACK/NACK transmission in the TTI is two Alternate in two OFDM symbols. The method of claim 8, wherein the plurality of ACK/NACK systems further utilize phase components orthogonal to each other. It is processed by multiplex. The method of claim 11, wherein the plurality of ACK/NACKs in the ACK/NACK group are further distinguished by the phase components for the plurality of ACK/NACKs. The method of claim 11, wherein the maximum number of the plurality of ACK/NACKs received using the predetermined number of the plurality of resource sets is a multiple of a predetermined number of the subcarriers, the sub A carrier system is included in each of the predetermined number of sets of resources. The method of any one of claims 8 to 13, wherein each of the different orthogonal codes has a length of "4", and each of the predetermined number of resource sets includes "4" The subcarriers, and the maximum number of one of the plurality of ACK/NACKs that are multiplexed in the ACK/NACK group is a multiple of "4".