Transmission control method and apparatus using delays in multiple antenna systems

ES 2 379 569 T3

DESCRIPTION

Transmission control method

Technical field

The present invention relates to wireless transmission devices and wireless transmission methods, and in particular to wireless transmission devices and wireless transmission methods for transmitting signals to wireless receiving devices through the use of various transmitting antennas. The present application claims the priorities of Japanese Patent Application No. 2005-253194 filed in Japan on September 1, 2005 and Japanese Patent Application No. 2005-367860 filed in Japan on December 21, 2005, both of which contents are incorporated herein by reference.

Background of the technique

Recently, methods have been provided, primarily adapted to multi-carrier transmission systems, in which a plurality of blocks are divided along frequency and time axes and which perform scheduling on signals transmitted to users from wireless transmission devices in units. of blocks. In this document, regions that are protected for communication by users and that are defined along the frequency and time axes are called allocation slots, and blocks that serve as the basis for determining allocation slots are called segments.

In the foregoing, methods are provided that, in order to transmit broadcast signals, multicast signals, and control signals, blocks are assigned whose extents are expanded in the direction of the frequency axis to produce frequency diversity effects, thus reducing errors regardless of low receive power. Furthermore, methods are provided that, in order to transmit unicast signals in one-to-one communications between wireless transmitting devices and wireless receiving devices, blocks whose extents are reduced in the direction of the frequency axis are allocated to produce effects of multi-user diversity, thus improving the reception power in wireless reception devices.

Figures 16A and 16B show the relationships in terms of signals transmitted from a wireless transmitting device to a wireless receiving device with respect to time (horizontal axis) and frequency (vertical axis). In Figure 16A, the horizontal axis represents time, and the vertical axis represents frequency. Transmission times t1 to t3 are set on the time axis. Herein, the same length of time is set at times t1 through t3 respectively. The transmit frequencies f1 to f5 are adjusted on the frequency axis. Herein, the same frequency range Fc is adjusted for frequencies f-ι to fs. With reference to the transmission times t1 to fe and the transmission frequencies fa f5, fifteen segments K1 to K15 are set as shown in FIG. 16A.

Furthermore, five segments K1 to K5 are connected, as shown in Figure 16B, and are then divided evenly into six slots along the time axis, thus adjusting communication slots s1 to s6 each of which has a time length of fe / 6 and a frequency interval of 5f₃. The communication slots s₁ and yes₄ they are assigned to a first user; communication slots s₂ and yes₅ are assigned to a second user; and the communication slots s₃ and yes₆ they are assigned to a third user. This makes it possible for first to third users to obtain frequency diversity effects.

The segment K10 is then assigned to a fourth user as a communication slot su. Segments K7, K8, and K9 are connected to form communication slots s8 to s10, each of which has a time length of t2 and a frequency interval of 3f1 and which are assigned to a fifth user. Also, segment K6 is assigned to a sixth user as a communication slot s7. This makes it possible for the fourth to sixth users to obtain multi-user diversity effects, and this makes it possible for the fifth user to obtain a frequency diversity effect.

Also, segment K11 is assigned to a seventh user as a communication slot s12. This makes it possible for this user to obtain a multi-user diversity effect. Also, segments K13 and K15 are assigned to an eighth user as communication slots s19 and s26. This makes it possible for this user to obtain a multi-user diversity effect. Furthermore, the two segments K12 and K14 are evenly divided into six slots, thus forming slots s13 to s18 and s20 to s25. Communication slots s13, s16, s20, and s23 are assigned to a ninth user; communication slots s14, s17, s21 and s24 are assigned to a tenth user; and communication slots s15, s18, s22 and s25 are assigned to an eleventh user. This makes it possible for ninth to eleventh users to obtain frequency diversity effects individually.

Document 1, which is not a patent: Contribution to 3GPP, R1-050249, “Downlink Multiple Access Scheme for EvolvedUTRA”, [Retrieved August 17, 2005], Internet (URL:

ES 2 379 569 T3 ftp://ftp.3gpp.org/TSG_RAN/WG1_RL1/TSGR1_40bis/ Docs / R1-050249.zip)

Document 2, which is not a patent: Contribution to 3GPP, R 1-050590, "Physical Channels and Multiplexing in Evolved UTRA Downlink", [Retrieved August 17, 2005], Internet (URL: ftp: // ftp. 3gpp.org/TSG_RAN/WG1_RL1/R1_Ad_Hocs/LTE_AH_June-05/Docs/R1-050590.zip)

The document by Bauch G. et al .: "Orthogonal Frequency Division Multiple Access with Cyclic Delay Diversity", 2004 ITG Workshop on Smart Antennas (Munich, Germany, March 18-19, 2004) reports that cyclic delay diversity is a simple transmit diversity technique for encoded OFDM systems with multiple transmit antennas. Cyclic delay diversity requires neither an extended guard interval nor modifications to the standard OFDM receiver. Bauch et al. discuss the problem of choosing cyclic delays and propose a solution that makes it possible to take advantage of full spatial diversity in frequency-selective and flat-fading channels with unknown delay spread. As a result, spatial diversity is transformed into frequency diversity between neighboring subcarriers. This imposes certain restrictions on the channel coding and interleaving scheme. In addition, they address multi-user aspects and propose a strategy of interleaving and multiple access that ensures that all users get the maximum possible diversity advantage using FEC codes with a limited restriction length. A performance comparison shows that space-time block codes perform better in cyclic delay diversity at the cost of greater complexity and less flexibility.

Description of the invention

Problems to be solved by the invention

In order to obtain frequency diversity effects in the above-mentioned conventionally known methods, it is necessary to increase the dispersion coefficients or reduce the coding coefficients in error-correcting coding in response to frequency variations of transfer functions in propagation paths.

Figures 17A and 17B and Figures 18A and 18B are graphs showing delay profiles and transfer functions with respect to signals propagating through various propagation paths having different delay times to reach wireless receiving devices.

Figures 17A and 18A show delay profiles showing transmission signals, propagating through various propagation paths to reach a wireless receiving device, with respect to time (horizontal axis) and power (vertical axis). Figures 17B and 18B show transfer functions for performing frequency conversion into delay profiles with respect to frequency (horizontal axis) and power (vertical axis).

Figure 17A shows the appearance of six delay waveforms W11 to w-ιβ, and Figure 18A shows the appearance of three delay waveforms w21 to w23. They differ from each other with respect to the maximum delay times t1 and t2.

When the maximum delay time t1 is long, as shown in Figures 17A and 17B, that is, when relatively fast frequency variations (rapid power variations in the frequency direction) occur in the transfer function, it is expected to produce an adequate frequency diversity effect regardless of a small dispersion coefficient and a high coding coefficient in error correction coding. However, when the maximum delay time t2 is small, as shown in Figures 18A and 18B, that is, when relatively moderate frequency variations occur in the transfer function, it is not expected to produce a diversity effect. suitable frequency when the dispersion coefficient is small and the coding coefficient in error correction coding is high; therefore, it is necessary to increase the dispersion coefficient and reduce the coding coefficient in error correction coding.

D1 and D2 in Figure 17B and Figure 18B show signals, that is, data. That is, in FIG. 17B, a spread spectrum technology spread ratio is set to "4" with respect to the D1 and D2 data, thereby assigning four subcarriers a11 to a14 to the D1 data. Similarly, four subcarriers a15 through a18 are assigned to the D2 data. In this case, the transfer function has rapid frequency variations; therefore, the receiving power of the a13 subcarrier for the D1 data is markedly decreased, so that the receiving power of the a16 a16 for the D2 data is markedly decreased as well. Therefore, no reception failure occurs with respect to the data D1 and D2.

In FIG. 18B, the dispersion ratio is set to "8" so that eight subcarriers a21 through a28 are assigned to the D1 data. In this case, the transfer function has slow frequency variations such that the reception power of the subcarrier a24 decreases markedly, and the reception power of the subcarriers a23 and

ES 2 379 569 T3 a25 decreases slightly, while the spread ratio of the data increases compared to the case of Fig. 17B so that no reception failure occurs with respect to the D1 data. The aforementioned values ​​of dispersion ratios are described for convenience and are not necessarily limited.

The present invention is made in consideration of the above-mentioned circumstances, it being an object of the invention to provide a wireless transmission device and a wireless transmission method that can produce a suitable frequency diversity effect without controlling a dispersion coefficient and a coefficient. coding in error-correcting coding on the wireless transmission side.

Means to solve the problem

According to the present invention, there is provided a transmission control method according to claim 1. Preferable features are set forth in claims 2 and 3.

Effect of the invention

With reference to the delay time T suitable for the communication signal, indicating either the transmission frequency diversity or the transmission multi-user diversity, the transmission signals supplied to the n transmission antennas are each delayed by the transmission time. delay (n-1) T or less.

Therefore, by appropriately adjusting the delay time T based on the condition whether the transmitting signals are subject to transmitting frequency diversity or transmitting multi-user diversity, it is possible to produce frequency diversity effects and multi-user diversity effects without being affected by the condition of a propagation path.

Brief description of the drawings

Fig. 1 is a schematic illustration showing that signals transmitted by a wireless transmitting device according to a first embodiment of the present invention propagate through various propagation paths to reach a wireless receiving device.

Figure 2A is a graph showing a delay profile applied to signals propagating through various propagation paths having different delay times to reach a wireless receiving device.

Figure 2B is a graph showing a transfer function that is produced by performing frequency conversion on the delay profile shown in Figure 2A.

Figure 3A is a graph showing another delay profile applied to signals propagating through various propagation paths that have different delay times to reach a wireless receiving device.

Figure 3B is a graph showing a transfer function of the wireless receiving device, which is produced by performing frequency conversion on the delay profile shown in Figure 3A.

Figure 3C is a graph showing a transfer function of another wireless receiving device located in a different position, which is produced by performing frequency conversion on the delay profile shown in Figure 3A.

Fig. 4A is a graph showing a maximum delay time (n-1) T in a delay profile.

Figure 4B is a graph showing the relationship between the maximum delay time (n-1) T shown in Figure 4A and frequency variations.

Fig. 5A is a graph showing another maximum delay time (n-1) T in a delay profile.

Figure 5B is a graph showing the relationship between the maximum delay time (n-1) T shown in Figure 5A and frequency variations.

Fig. 6A is an illustration showing a wireless transmission / reception system, in which the same signal without a delay time is transmitted through several antennas of a wireless transmission device.

ES 2 379 569 T3

Fig. 6B is a graph showing an example of a receive signal in the system shown in Fig. 6A.

Figure 6C is a graph showing another example of a receive signal in the system shown in Figure 6A.

Fig. 7A is an illustration showing a wireless transmission / reception system, in which the same signal is applied with different delay times and is then transmitted through several transmitting antennas of a wireless transmission device.

Fig. 7B is a graph showing an example of a receive signal in the system shown in Fig. 7A.

Figure 7C is a graph showing another example of a receive signal in the system shown in Figure 7A.

Fig. 8 is a block diagram showing the configuration of a physical layer of a wireless transmission device according to a second embodiment of the present invention.

Fig. 9A shows an example of a signal that is produced by applying a flow delay to a transmission signal according to a third embodiment of the present invention.

Fig. 9B shows another example of a signal that is produced by applying a flow delay to a transmission signal according to the third embodiment of the present invention.

Fig. 10 is a block diagram showing the configuration of a physical layer of a wireless transmission device according to the third embodiment of the present invention.

Fig. 11 is an illustration for explaining the operation of a section 119-1 for imparting flow retardation in the third embodiment of the present invention.

Fig. 12 is a block diagram showing the configuration of a physical layer of a wireless transmission device according to a fourth embodiment of the present invention.

Fig. 13 is a block diagram showing the configuration of a physical layer of a wireless transmission device according to a fifth embodiment of the present invention.

Figure 14 is a table showing the relationship between the maximum delay time (n-1) T between transmitting antennas and a frequency bandwidth Fc of a segment with respect to each physical channel.

Figure 15 is a table showing another relationship between the maximum delay time (n-1) T between transmitting antennas and the frequency bandwidth Fc of a segment with respect to each physical channel.

Fig. 16A is a graph showing the relationship between signals, which are transmitted from a wireless transmitting device to a wireless receiving device, with respect to time (horizontal axis) and frequency (vertical axis).

Figure 16B is a graph showing communication slots that are assigned to a time-frequency space shown in Figure 16A.

Figure 17A is a graph showing a delay profile adapted to signals propagating through various propagation paths with different delay times to reach a wireless receiving device.

Figure 17B is a graph showing a transfer function that is produced by performing frequency conversion on the delay profile shown in Figure 17A.

Fig. 18A is a graph showing a delay profile adapted to signals propagating through propagation paths with different delay times to reach a wireless receiving device.

Fig. 18B is a graph showing a transfer function that is produced by performing frequency conversion on the delay profile shown in Fig. 18A.

ES 2 379 569 T3

Best Mode of Carrying Out the Invention (First Embodiment)

Fig. 1 is a schematic illustration showing that signals transmitted from a wireless transmitting device 1 propagate through various propagation paths to reach a wireless receiving device 7. The wireless transmission device 1 has several transmission antennas 2 to 4, to which different delay times 0, T and 2T are applied respectively and from which signals are transmitted. The wireless receiving device 7 receives signals transmitted from the wireless transmitting device 1. Fig. 1 shows an example in which the wireless transmission device 1 is equipped with three transmission antennas 2 to 4.

Several transmitting antennas are assumed to be transmitting antennas installed in a wireless transmitting device provided in a base station for mobile phones, three types of transmitting antennas being provided with respect to different sectors of the same base station and with respect to different base stations. The following description is given with respect to the situation where they belong to the same sector, for example, although it is possible to use another constitution. That is, n transmitting antennas belong to different sectors, n transmitting antennas belong to different base stations. In the figure, delays 5 and 6 apply a delay time T, whereby, as described above, the delay time T is applied to the transmitting antenna 3, and the delay time 2T is applied to the transmitting antenna 4.

Figures 2A and 2B show a delay profile and a transfer function with respect to signals, which propagate through several (three) propagation paths with different delay times to reach a wireless receiving device. Figure 2A shows the delay profile showing that transmission signals propagate through various propagation paths with different delay times to reach the wireless receiving device with respect to time (horizontal axis) and power (vertical axis ). As shown in Figure 2A, the delay profile has, instantaneously, a maximum delay waveform of 2T + dmax; therefore, compared to the constitution in which the same signal is transmitted through each transmitting antenna, the maximum delay waveform becomes very large. Herein, dmax represents a time of arrival difference between a fast propagation path and a slow propagation path when radio waves arrive at a receiving antenna from a transmitting antenna.

Figure 2B shows a transfer function that is produced by performing frequency conversion in the delay profile of Figure 2A with respect to frequency (horizontal axis) and power (vertical axis). In the delay profile, the increasing maximum delay time 2T + dmax indicates rapid frequency variations of the transfer function. Thus, as shown in Figure 2B (similarly to Figure 17B), the D1 and D2 data are spread with a spread ratio of "4" and assigned subcarriers. It is preferable that the dispersion coefficient or the error correction coding coefficient is controlled in response to frequency variations of the transfer function in the wireless transmission device 1, the above-mentioned method asserting that the delay time 2T it is recognized in advance by the wireless transmission device 1; therefore, it is possible to determine the dispersion coefficient or the error correction coding coding coefficient independently of frequency variations of propagation paths. To produce multi-user diversity effects, it is preferable that the maximum delay time 2T + dmax, which appears instantaneously in the delay profile, is not increased so much. Multi-user diversity effects will be described with reference to Figures 3A to 3C.

Figures 3A to 3C show a delay profile and transfer functions with respect to signals propagating through various propagation paths with different delay times to reach a wireless receiving device. Figure 3A shows the delay profile adapted to transmission signals propagating through several (three) propagation paths with different delay times to reach the wireless receiving device with respect to time (horizontal axis) and power ( vertical axis). Figure 3B shows a handover function with respect to a wireless receiving device used by a user u1. Figure 3C shows a handover function with respect to a wireless receiving device used by a user u2. Since the wireless receiving devices of users u1 and u2 differ from each other in location, their instant transfer functions differ from each other.

Assuming that a left region is connected to a frequency channel b1 and a right channel is connected to a frequency channel b2 in Figures 3B and 3C, the user u1 enjoys good quality on the frequency channel b2, while the user u2 enjoys good quality on frequency channel b1. Therefore, data D1 to D4 is transmitted to user u1 on frequency channel b2. Data D1 to D4 are spread spectrum. Data D1 to D4 is transmitted to user u2 on frequency channel b1. In this case, the data D1 to D4 are spectralized.

As described above, by using a quality difference between frequency channels at a given time, it is possible to produce multi-user diversity effects to improve the efficiency of the

ES 2 379 569 T3 transmission with respect to different users conducting communications using different frequency channels. However, when the maximum delay time 2T + d_max increases too much, rapid frequency variations occur in the transfer function, thus reducing the quality difference between frequency channel b1 and frequency channel b2. Therefore, to produce suitable multi-user diversity effects, it is important to reduce the maximum delay time 2T + dmax as shown in Figure 3A.

Figures 4A and 4B and Figures 5A and 5B show the relationships between the maximum delay time (n-1) T and frequency variations. When a time of arrival difference (n-1) T appears between incoming waves w31 and w32 as shown in Figure 4A, a transfer function of this propagation path is shown in Figure 4B. That is, a frequency difference between power amplitude drops (vertical axis) is defined as F-1 / (n-1) T. When several delay waves w41 to w43 appear as shown in Figure 5A, a difference in time of arrival (n-1) T appears between the first incoming wave w41 and the last incoming wave w43, so that a difference of frequency between power amplitude drops (vertical axis) is defined as F = 1 / (n-1) T as shown in Figure 5B.

In this regard, the frequency diversity effect differs from the multi-user diversity effect in terms of frequency variations of appropriate transfer functions thereof; therefore, in order to produce the frequency diversity effect, the maximum delay time (n-1) T is set as (n - 1) T> 1 / Fc, where Fc indicates a frequency bandwidth of a segment, which is a basic region protected by the user for communication and defined with respect to the frequency axis and the time axis, thus creating an environment that easily produces the effect of frequency diversity.

Instead, in order to produce the multi-user diversity effect, the maximum delay time (n-1) T is set as (n-1) T <1 / Fc, where Fc indicates a frequency bandwidth of a segment, thus creating an environment that easily produces the effect of multi-user diversity. In the following description, an inequality of (n-1) T <1 / Fc encompasses (n-1) T = 0. In the following description, the delay times applied to transmitting antennas are each represented as (n-1) multiples of T, assuming that T is constant, although it is possible to change T with respect to each of the transmitting antennas. In order to produce the multi-user diversity effect, it is possible to reduce the maximum delay time by reducing the number of transmitting antennas used for transmission instead of adjusting the inequality of (n-1) T <1 / F_c. As described above, in response to a determination as to whether the transmit signals are subjected to transmit frequency diversity or transmit multi-user diversity (i.e., (n-1) T> 1 / Fc or (1- n) T <1 / Fc), it is possible to produce the frequency diversity effect or the multi-user diversity effect without being affected by propagation path conditions.

As shown in Fig. 16A, regarding the first user who performs communication by means of the communication slot s1 which is produced by connecting several consecutive segments in the frequency direction and the user who is assigned discontinuous segments such as the ninth user assigned communication slots s13, s16, s20, and s23, the bandwidth BW (that is, BW = 5F for the first user, and BW = 3F for the ninth user) of a communication slot instantly assigned to the user defines the basis for the realization of the frequency diversity effect; therefore, by setting the maximum delay time as (n-1) T> 1 / BW, it is possible to produce the effect of frequency diversity. For example, the delay time T is adjusted so that the maximum delay time (n-1) T between transmitting antennas falls within the range of (n-1) T> 1 / BW when a communication signal indicates the frequency diversity effect, while the delay time T is adjusted so that the maximum delay time (n-1) T between transmitting antennas falls within the range of (n-1) T <1 / Fc. Although not illustrated, when a subcarrier included partially in several segments is assigned to a certain user, the BW bandwidth of a communication slot assigned to the user represents a frequency difference between the subcarriers, which deviate from each other at most on the subcarriers instantly assigned to the user. The determination as to whether the signals are subjected to frequency diversity transmission or multi-user diversity transmission may change based on types of transmission signals (e.g., pilot signals, control signals, broadcast / multicast signals, and similar), wireless reception device travel speeds (frequency diversity being selected in case of high travel speed, and selecting multi-user diversity in case of low scrolling speed), and the like.

Figures 6A to 6C are explanatory drawings of the situation where the same signal without delay time is transmitted through several antennas of a wireless transmission device 8. It is assumed that, as shown in Fig. 6A, the wireless transmission device 8 is equipped with several (three) transmission antennas, which are arranged in parallel and have no directivity in the horizontal direction. Due to the appearance of lobes e11 and e12 indicated by ellipses shown in figure 6A, there is an address that provides a wireless reception device 9 that receives reception signals with a high reception level with respect to all frequency bands (see Fig. 6B) and an address having a wireless receiving device 10 that receives reception signals with a low reception level with respect to all frequency bands (see Fig. 6C).

ES 2 379 569 T3

Figures 7A to 7C are explanatory drawings in which the same signal is applied with different delay times respectively and is then transmitted through several transmitting antennas of the wireless transmitting device 8. The wireless transmission device 8 is supposed to be equipped with several (three) non-directivity transmission antennas, which are arranged in parallel. Due to the appearance of lobes e21 to e26 in narrow bands, a frequency band is produced that guarantees a high level of reception and a frequency band that guarantees a low level of reception in the reception signals, while maintaining a level of substantially constant average reception regardless of directions; therefore, it is possible to guarantee substantially the same quality with respect to both the reception level of a wireless receiving device 9 (see FIG. 7B) and the reception level of a wireless receiving device 10 (see FIG. 7C). Thus, the method, in which signals with different delay times are applied and then transmitted through transmitting antennas of the wireless transmission device 8, compensates for the drawbacks of the method, which is described with reference to FIGS. 6A through FIGS. 6C and in which the same signal is transmitted through several transmitting antennas.

(Second realization)

A second embodiment of the present invention will be described with respect to the constitution of a wireless transmission device. Similar to the wireless transmission device 1 of the first embodiment (see Fig. 1), the wireless transmission device of the present embodiment has several transmission antennas. The wireless transmission device described below is a wireless transmission device in which different delay times are applied to transmission antennas to transmit signals, in which delay times are imparted in a time region. In the present embodiment, signals are described to which different delay times are applied in connection with transmitting antennas in such a way that a signal, which is delayed T with respect to a transmitting signal actually transmitted from a first transmitting antenna, is transmits through a second transmitting antenna, and similarly, an nth transmitting antenna transmits a delayed signal (n-1) T.

Fig. 8 is a block diagram showing the configuration of a physical layer of the wireless transmission device of the present embodiment. The physical layer represents a part of the wireless transmission device configuration, in particular, that receives transmission signals, performs signal processing in a way that can be transmitted wirelessly, and forwards signals to a wireless frequency converter to perform frequency conversion to wireless frequencies. As shown in Figure 8, the physical layer includes user-dependent signal processors 11a and 11b and antenna-dependent signal processors 12-1, 12-2, and 12-3. User-dependent signal processor 11a (similar to user-dependent signal processor 11b) performs signal processing on signals to be transmitted to a wireless receiving device used by each user. The antenna-dependent signal processor 12-1 (similarly to the antenna-dependent signal processors 12-2 and 12-3) performs signal processing with respect to each of the transmitting antennas.

The user dependent signal processor 11a includes an error correction coding section 13, a modulator 14, a subcarrier assignment section 15, an IFFT (inverse fast Fourier transform) section 16, a parallel conversion section 17 -series, a section 18 to impart GI (guard interval), and sections 19-1, 19-2 and 19-3 to impart delay. The error correction coding section 13 performs error correction coding on transmission signals. Modulator 14 performs modulation processing such as QPSK (Quadrature Phase Shift Switching) and 16QAM (Quadrature Amplitude Modulation) on the output of error correction coding section 13.

Subcarrier assignment section 15 assigns the output of modulator 14 to appropriate subcarriers based on subcarrier assignment information indicated by a higher order layer. IFFT section 16 performs frequency-time conversion on the output of subcarrier allocation section 15. The parallel-serial conversion section 17 performs parallel-serial conversion on the output of the IFFT section 16. GI imparting section 18 imparts guard intervals to the output of parallel-serial conversion section 17. Section 19-1 for imparting delay imparts different delays to the output of section 18 for imparting GI in connection with transmit antennas.

The outputs of sections 19-1 through 19-3 for imparting delay are supplied to antenna-dependent signal processors 12-1, 12-2, and 12-3 respectively. Sections 19-1 through 19-3 for imparting delay provide different delays (for example, 0, S, and 2S). In this document, S = T / (sample time). The sample time represents a minimum time interval between digital signals, which are processed in section 18 to impart GI, sections 19-1 through 19-3 to impart delay, and section 20 to mix. Thus, imparting a delay of S samples in sections 19-1 through 19-3 to impart delay indicates that a time delay T is imparted at the output terminal of the D / A converter 22. The user dependent signal processor 11a is used in a certain segment; in other words, it is used either in a region of frequency diversity or in a region of multi-user diversity; therefore, it receives a communication signal (multi-user div. frequency / div. communication signal) indicating the use of either the frequency diversity region or the region

ES 2 379 569 T3 of multi-user diversity from the higher order layer controlling the physical layer. The user-dependent signal processor 11a selectively uses either the frequency diversity region or the multi-user diversity region based on the communication signal, thus operating to change the delay time T. The user-dependent signal processor 11b has a constitution similar to that of the user-dependent signal processor 11a, but differs from it in terms of the user thereof.

The antenna-dependent signal processor 12-1 includes the mixing section 20, a filter 21, and a D / A (digital / analog) converter 22. The mixing section 20 adds together and mixes signals, which are output to the antenna-dependent signal processor 12-1 from the user-dependent signal processors 11a and 11b. Filter 21 extracts signals from a prescribed band only from the output of mixing section 20. The D / A converter 22 performs digital-to-analog conversion at the output of filter 21. Both antenna-dependent signal processors 12-2 and 12-3 are similar in constitution to that of antenna-dependent signal processor 12-1. . The output of the antenna-dependent signal processor 12-1 is forwarded to a wireless frequency converter (not shown) to perform frequency conversion to wireless frequencies, from which it is supplied to several (three) transmitting antennas, thereby transmitting wireless signals.

(Third embodiment)

A third embodiment of the present invention will be described with respect to another constitution of a wireless transmission device. The wireless transmission device of the present embodiment is a wireless transmission device that applies different delay times to transmitting antennas to transmit signals, wherein delay times are applied with respect to a time region. The wireless transmission device handles signals, to which guard intervals are applied with respect to symbols (valid symbol intervals) of transmission signals. Signals to which different delay times are applied with respect to transmitting antennas are centered on prescribed parts (valid symbol intervals) of transmitting signals, which are actually transmitted through a first transmitting antenna except for the intervals of guard; therefore, only valid symbol intervals T are delayed and then transmitted through a second transmitting antenna; similarly, only valid symbol intervals (n-1) T are delayed and then transmitted through an nth transmitting antenna.

Thus, transmitting antennas transmit signals, to which guard intervals are applied in correspondence with valid symbol intervals; thus, unlike the second embodiment, there is no time deviation in the symbol timing at the transmitting antennas. A method of imparting delay time described above is referred to as "for imparting circulation delay" in the following description. By means of processing to impart circulation delay, ensuring delay waves is advantageous compared to the second embodiment which describes that delay times are applied to transmitting antennas.

Figures 9A and 9B show examples of signals that are produced by imparting flow delays to transmission signals in the present embodiment. Figure 9A shows a signal transmitted through a first antenna, and Figure 9B shows a signal transmitted through a second antenna. Figures 9A and 9B show that the valid symbol interval corresponds to four samples and the guard interval corresponds to one sample, in which with respect to the valid symbol interval, a sample is delayed in the second antenna compared to the first. antenna. There is no symbol timing deviation in symbol units with respect to the first antenna and the second antenna; therefore, even when a flow delay is applied thereto, it is recognized that a guard interval effect is maintained to enhance against interference with adjacent symbols.

Fig. 10 is a block diagram showing the physical layer configuration of the wireless transmission device according to the present embodiment. As shown in the figure, the physical layer includes user-dependent signal processors 111a and 111b and antenna-dependent signal processors 112-1, 112-2, and 112-3. User-dependent signal processor 111a (similar to user-dependent signal processor 111b) performs signal processing in connection with a wireless transmission device used by each user. The antenna-dependent signal processor 112-1 (similarly to the antenna-dependent signal processors 112-2 and 112-3) performs signal processing with respect to a prescribed transmit antenna. The constitution of the user-dependent signal processor 111a is substantially identical to the constitution of the user-dependent signal processor 111a (FIG. 8) described in the second embodiment, although a difference between them is that section 18 is not provided to impart GI, and sections 119-1 to 119-3 are provided to impart flow retardation instead of section 19-1 to 19-3 to impart retardation. The user dependent signal processor 111a shares the same functions as the built-in error correction coding section 13, modulator 14, subcarrier allocation section 15, IFFT section 16, and parallel-serial conversion section 17. in the second embodiment (see figure 8); therefore, they are designated by the same reference numbers, and their description will be omitted.

Section 119-1 for imparting circulation delay imparts different circulation delays at the exit of the

ES 2 379 569 T3 section 17 of parallel-serial conversion in connection with transmitting antennas. The outputs of sections 119-1 through 119-3 for imparting travel delay are supplied to antenna-dependent signal processors 112-1, 112-2, and 112-3. In addition, sections 119-1 to 119-3 for imparting travel delay provide different delays (eg, 0, S, and 2S). In this document, S = T / (sample time). The user dependent signal processor 111a is used in a certain segment. Since it is used in either the frequency diversity region or the multi-user diversity region, it receives a communication signal indicating the use of either the frequency diversity region or the multi-user diversity region by means of the higher order layer that controls the physical layer. The user-dependent signal processor 111a selectively uses either the frequency diversity region or the multi-user diversity region based on the communication signal, thus operating to change the delay time T. The dependent signal processor 111b The user has a constitution similar to that of the user-dependent signal processor 111a, but differs from the user in terms of the user.

Fig. 11 is an illustration for explaining section 119-1 for imparting running delay, which is described as an example of the present embodiment. Section 119-1 for imparting circulation delay is equipped with a memory 110. To impart a flow delay of k samples, D11 data is input sequentially from address k + 1 to address n of memory 110 (i.e. 1, 2, 3, ..., (nk) are input ); then, a subsequence of the D11 data is entered at address 1 (that is, (n-k + 1), (n-k + 2), (n-k + 3), ..., n are entered) ), thus introducing n samples of the data D11. Next, by sequentially extracting from address 1 of memory 110, it is possible to output data D12, which is produced by imparting a circulation delay of k samples to the n samples of data D11, (that is, (n-k + 1 ), (n-k + 2), (n-k + 3), ..., n, 1, 2, ..., (nk)). Figure 9A shows an example of the signal, which is produced by imparting a zero sample flow delay to four sample data, and Figure 9B shows an example of the signal, which is produced by imparting a flow delay of one sample.

The constitution of the antenna-dependent signal processor 112-1 (Figure 10) is substantially identical to the constitution of the antenna-dependent signal processor 12-1 (Figure 8) described in the second embodiment, where a difference between them resides in which section 18 is provided for to teach GI. The functions of the mixing section 20, the section 18 for imparting GI, the filter 21 and the D / A converter 22 included in the antenna-dependent signal processor 112-1 are identical to those incorporated in the second embodiment (Figure 8); therefore, they are designated by the same reference numbers, and their description will be omitted. Both antenna-dependent signal processors 112-2 and 112-3 are similar in constitution to that of antenna-dependent signal processor 112-1. The outputs of the antenna-dependent signal processors 112-1, 112-2, and 112-3 are supplied to a wireless frequency converter (not shown) to perform frequency conversion to wireless frequencies, from which they are supplied to various (three) transmitting antennas, thus transmitting wireless signals.

(Fourth embodiment)

A fourth embodiment of the present invention will be described with reference to the constitution of another wireless transmission device. The wireless transmission device of the present embodiment is a wireless transmission device in which different delay times are applied to transmitting antennas to transmit signals, in which delay times are applied with respect to a frequency region. The present embodiment deals with signals to which guard intervals are applied with respect to symbols (valid symbol intervals) of transmission signals, in which similarly to the wireless transmission device of the third embodiment (Fig. 10), they impart circulation delays to them.

Fig. 12 is a block diagram showing the physical layer configuration of the wireless transmission device of the present embodiment. As shown in the figure, the physical layer includes user-dependent signal processors 211a and 211b, a subcarrier allocation section 215, and antenna-dependent signal processors 212-1, 212-2, and 212-3. User-dependent signal processor 211 a (similarly to user-dependent signal processor 211b) performs signal processing with respect to a wireless transmission device used by each user. The subcarrier assignment section 215 assigns the output of the user dependent signal processor 211a to each subcarrier. The antenna-dependent signal processor 212-1 (similarly to the antenna-dependent signal processors 212-2 and 212-3) performs signal processing relative to a prescribed antenna.

Each of the user dependent signal processors 211a and 211b includes an error correction coding section 13 and a modulator 14. The functions of the error correction coding section 13 and modulator 14 are substantially identical to those described. in the second embodiment (figure 8); therefore, they are designated by the same reference numbers, and their description will be omitted. The outputs of the user-dependent signal processors 21 a and 211 b are assigned appropriate subcarriers in the subcarrier assignment section 215 based on subcarrier assignment information indicated by the higher order layer; then, antenna-dependent signal processors 212-1, 212-2, and 212-3 are supplied.

ES 2 379 569 T3

The antenna-dependent signal processor 212-1 includes a phase rotation section 219, an IFFT section 16, a parallel-serial conversion section 17, a section 18 for imparting GI, a filter 21, and a D converter 22. /TO. The functions of the IFFT section 16, the parallel-serial conversion section 17, the section 18 for imparting GI, the filter 21 and the D / A converter 22 are identical to those described in the second embodiment (Figure 8); therefore, they are designated by the same reference numbers, and their description will be omitted. The phase rotation section 219 rotates the output of the subcarrier allocation section 215 in phase 0m with respect to each subcarrier and then outputs it to the IFFT section 16. Both antenna-dependent signal processors 212-2 and 212-3 have a constitution similar to the constitution of antenna-dependent signal processor 212-1.

The outputs of the antenna-dependent signal processors 212-1, 212-2, and 212-3 are supplied to a wireless frequency converter (not shown) to perform frequency conversion to wireless frequencies, from which they are supplied to various transmitting antennas, thus emitting wireless signals. In the present embodiment, the phase rotation 0m in the phase rotation section 219 is set to 0m = 2zfm- (n-1) T. In this document, fm indicates a frequency difference between the 0-th subcarrier and the mth subcarrier, being defined as fm = m / Ts, so that (n-1) T represents a circulation delay time in the nth antenna in connection with a first antenna. Ts represents a valid symbol time for an OFDM symbol.

A section 220 for imparting delay is constituted by the phase rotation section 219 and the IFFT section 16. The phase rotation applied by the phase rotation section 219 is subjected to frequency-time conversion in the IFFT section 16, so that it is considered as a time delay in the output of the IFFT section 16. The user-dependent signal processor 211a is used in a certain segment, which is used either in the frequency diversity region or in the multi-user diversity region, where it receives a communication signal indicating whether to use the frequency diversity region or the multi-user diversity region from a higher order layer controlling the physical layer. Based on the communication signal, the user-dependent signal processor 211a selectively uses the frequency diversity region or the multi-user diversity region, thus operating to change the delay time T.

The wireless transmission devices according to the second to fourth embodiments are each equipped with with a section for imparting delay to delay supplied transmission signals to n (n is an integer of two or more) transmitting antennas the maximum delay time (n-1) T according to the delay time T suitable for a communication signal indicating whether the transmission signals are subjected to frequency diversity transmission or multi-user diversity transmission. Therefore, by appropriately adjusting the delay time T based on determining whether the transmission signals are subjected to the frequency diversity transmission or the multi-user diversity transmission, it is possible to produce the frequency diversity effect and the diversity effect. multi-user without being affected by propagation path conditions.

(Fifth realization)

A fifth embodiment of the present invention will be described with respect to the constitution of another wireless transmission device. The wireless transmission device of the present embodiment is a wireless transmission device that applies different delay times to signals, which are then transmitted through transmitting antennas, in the region of frequency diversity while applying appropriate weights to the antennas. transmission to perform directivity control in the multi-user diversity region, in which delay times are applied and directivity control is performed in the frequency region. The present embodiment deals with signals that are produced by imparting guard intervals to transmission signals with respect to symbols (valid symbol intervals), wherein, similarly to the third and fourth embodiments, circulation delays are imparted to the signals. .

Fig. 13 is a block diagram showing the configuration of a physical layer of the wireless transmission device of the present embodiment. As shown in the figure, the physical layer includes user-dependent signal processors 211 a and 211b, a subcarrier assignment section 215, a weight calculation section 310, and processors 312-1, 312-2, and 312-3. antenna-dependent signals. The constitutions of the user dependent signal processor 211a and the subcarrier allocation section 215 are similar to those of the fourth embodiment (FIG. 12); therefore, they are designated by the same reference numbers, and their description will be omitted.

The antenna-dependent signal processor 312-1 (similarly to the antenna-dependent signal processors 312-2 and 312-3) performs signal processing relative to a prescribed transmit antenna. The antenna dependent signal processor 312-1 includes a weighted multiplication section 319, an IFFT section 16, a parallel-serial conversion section 17, a section 18 for imparting GI, a filter 21, and a D / D converter 22. TO. The functions of the IFFT section 16, the serial parallel conversion section 17, the GI imparting section 18, the filter section 21 and the D / A converter 22 are identical to those of the first embodiment; therefore, they are designated by the same reference numbers, and their description will be omitted.

ES 2 379 569 T3

Weighted multiplication section 319 performs weighted multiplication on the output of subcarrier assignment section 215 with respect to subcarriers, and outputs the results to IFFT section 16. Both antenna-dependent signal processors 312-2 and 312-3 have a constitution similar to that of antenna-dependent signal processor 312-1. The outputs of the antenna-dependent signal processors 312-1, 312-2, and 312-3 are supplied to a wireless frequency converter (not shown) to perform frequency conversion to wireless frequencies, from which the results are supplied. to transmitting antennas, thus emitting wireless signals.

A specific subcarrier is used in a certain segment. That is, it is used either in the frequency diversity region or in the multi-user diversity region. The weighted multiplication section 319 is informed about the determination of whether to use either the frequency diversity region or the multi-user diversity region from the higher-order layer controlling the physical layer, based on which it is input phase rotation 0_m in order to apply different delay times to antennas in the frequency diversity region, while multiplying using a wm weight in order to perform directivity control in the multi-user diversity region.

A section 320 for imparting delay and directivity control is constituted by the weighted multiplication section 319 and the IFFT section 16. When phase rotation is input by means of the weighted multiplication section 319, it is considered as a time at the output of IFFT section 16 since IFT section 16 performs frequency-time conversion. On the other hand, when the weighted multiplication section performs multiplication using the wm weights, the IFFT section 16 performs frequency-time conversion so that the output of the IFFT section 16 emitted from the transmitting antenna is subjected to directivity control. .

When weighted multiplication section 319 rotates phase 0_m, similarly to the fourth embodiment, set 0m = 2xfm- (n-1) T. In this document, fm indicates a frequency difference between the 0-th subcarrier and the m-th subcarrier, where f_m= m / T_s; and (n-1) T represents a circulation delay time in the nth antenna in connection with a first antenna. Ts represents a valid symbol time for an OFDM symbol. To perform multiplication using wm weight, adjust the following weight to perform directivity control. Assuming a linear arrangement of n antennas whose distance is half a wavelength of a carrier frequency, the weight Wm is calculated according to the following equation (1):

[Equation 1]

<img file="ES2379569T3_D0001.tif" />

The weight wm represents a vector of a weight used in the weighted multiplication section 319, where, in equation (1), the terms first to last describe the weights used in the first to nth antennas. In equation (1) expressing the weight wm, n indicates the number of antennas, where, in the present embodiment, n = 3; 0 indicates a direction in which a main beam is directed; and k indicates a ratio between the frequency used for transmission and the frequency that is measured based on 0. With respect to the main beam direction 0, a measured value produced by the wireless transmission device or a terminal of a counter-communicator is supplied to the weight calculation section 310, where it is used to calculate the weight w_m. Equation (1) presents an example calculation for the weight wm, which can be calculated by another method. The calculation methods for 0 and wm are described in the document "Technical Report RCS2004-229" (published by the Corporate Institute of electronic Information and Telecommunication, in November 2004) and the like.

Section 320 for imparting delay and directivity control imparts a delay of the maximum delay time (n1) T or less between transmitting antennas when the communication signal indicates frequency diversity, while performing multiplication to produce the weight wm to realize directivity control when the communication signal indicates multi-user diversity. As described in the first embodiment, the section 320 for imparting delay and directivity control adjusts the delay time T so that the maximum delay time (n-1) T between transmitting antennas falls within the range of ( n-1) T&gt; 1 / F_c when the communication signal indicates frequency diversity. As described in the first embodiment, the section 320 for imparting delay and directivity control adjusts the delay time T so that the maximum delay time (n-1) T falls within the range of (n-1) T&gt; I / BW when the communication signal indicates frequency diversity.

The above-mentioned description teaches that the weighted multiplication section 319 of the section 320 for imparting delay and directivity control receives instructions from the higher-order layer controlling the

ES 2 379 569 T3 physical layer to use either the frequency diversity region or the multi-user diversity region, based on which it applies a 0m phase rotation to impart different delay times to antennas in the frequency diversity region , while performing multiplication to produce the weight wm to perform directivity control in the multi-user diversity region; however, it is possible to use another method to use both the 0m phase rotation and the Wm weight in the multi-user diversity region such that, as described in the fourth embodiment, the 0m phase rotation is imparted with respect to both the frequency diversity region as the multi-user diversity region before the main beam direction 0 occurs, and then directivity control is performed using the weight Wm after the main beam direction 0 has been produced in the multi-user diversity region. Similar to the fourth embodiment, the delay time T varies in connection with 0m according to the frequency diversity region and the multi-user diversity region. Therefore, in the phase before the main beam direction 0 occurs, it is possible to produce the same multi-user diversity effect as in the fourth embodiment, whereas after the main beam direction 0 occurs, it is expected to produce a higher multi-user diversity effect strictly realizing directivity control using weight w_m. Furthermore, by using the physical layer configuration of the wireless transmission device shown in Fig. 13 instead of the fourth embodiment, it is possible to realize the characteristic improvement due to directivity control by slightly increasing the circuit constitution.

As described above, the section 320 for imparting delay and directivity control imparts a delay of the maximum delay time (n-1) T or less between transmitting antennas when the communication signal indicates frequency diversity, while imparting a delay of the maximum delay time (n-1) T or less between transmitting antennas, or perform multiplication to produce the weight Wm to perform directivity control when the communication signal indicates multi-user diversity.

The wireless transmission device that performs the aforementioned processing has the constitution shown in Fig. 13, in which, when the communication signal indicates multi-user diversity, the section for imparting delay and directivity control imparts a delay of the time of maximum delay (n-1) T or less between transmitting antennas, or perform multiplication to produce weight Wm to perform directivity control.

As described in the first embodiment, the section for imparting delay and directivity control adjusts the delay time T so that the maximum delay time (n-1) T between transmitting antennas falls within the range of (n -1) T&gt; 1 / Fc when the communication signal indicates frequency diversity, while adjusting the delay time T so that the maximum delay time falls within the range of (n-1) T &lt;1 / Fc when the communication signal indicates multi-user diversity so that a delay is applied between transmitting antennas . As described in the first embodiment, the section for imparting delay and directivity control adjusts the delay time T so that the maximum delay time (n-1) T between transmitting antennas falls within the range of (n -1) T&gt; 1 / BW when the communication signal indicates the frequency diversity.

The aforementioned second to fifth embodiments are described with respect to the case where the number of users is two and the number of antennas is three, although the number of users and the number of antennas is not necessarily limited to these numbers. In the aforementioned fourth to fifth embodiments, it is possible to transmit signals, which are subjected to multiplication using specific scrambling codes depending on antennas, sectors and base stations, to transmitting antennas.

(Sixth embodiment)

The present embodiment will be described with respect to variations of the maximum delay time (n-1) T depending on the physical channels. The aforementioned first to fifth embodiments are described assuming that one-to-one communication is performed with respect to a certain segment at a certain time, where (n-1) T&gt; 1 / Fc is adjusted to produce the effect of frequency diversity. , while (n-1) T &lt;1 / Fc is adjusted to produce the multi-user diversity effect.

Typically, in communications other than one-to-one communication, a known signal called a pilot channel is transmitted to a wireless transmission device in order to estimate a propagation path; alternatively, a control channel is used to report various types of parameters prior to data communication. The present embodiment will be described with respect to a method of setting the maximum delay time (n-1) T on these physical channels.

In the Evolved UTRA &amp; UTRAN standard examined in 3GPP (3rd Generation Partnership Project), common pilot channels DCPCH (Downlink Common Pilot Channel), dedicated pilot channels DDPCH (Downlink Dedicated Pilot Channel), channels of DSCH (Downlink Synchronization Channel) downlink synchronization, DCCCH (Downlink Common Control Channel) common control channels, DSCSCH downlink shared control signaling channels

ES 2 379 569 T3 (Downlink Shared Control Channel), and multicast / broadcast channels (Multicast / Broadcast Channel).

The common DCPCH pilot channels correspond to CPICH pilot channels in W-CDMA (Wideband Code Division Multiple Access), which are used for the estimation of conditions of downlink propagation paths, search for cells and measurement of propagation path losses in uplink transmission power control in AMCS (Adaptive Modulation and Coding Scheme). Dedicated DDPCH pilot channels are used to transmit to individual mobile stations through transmitting antennas such as adaptive network antennas whose propagation paths (directivities) differ from those of cell-sharing antennas; alternatively, they can be used in order to reinforce shared common DSPCH downlink pilot channels in connection with mobile stations having poor reception qualities.

DSCH downlink synchronization channels correspond to SCH synchronization channels in WCDMA, where they are used for cell search of mobile stations, OFDM (Orthogonal Frequency Division Multiplexing) wireless signal frames, time slots , TTI (Transmission Timing Interval) timing intervals, and OFDM symbol timing timing. DCCCH common control channels include common control information such as broadcast information (corresponding to BCH broadcast channels) corresponding to P-CCPCH primary common control physical channels, S-CCPCH secondary common control physical channels, and PICH paging indicator in W-CDMA, packet paging indicator PI information (corresponding to PICH paging indicator channels) designating the occurrence of packet calls, packet paging information (corresponding to PCH paging channels) corresponding to packet calls, and information downlink access channel (corresponding to FACH downlink access channels).

DSCSCH downlink shared control signaling channels correspond to shared control channels connected with HS-DSCH, HS-SCCH, DPCCH downlink dedicated control channels, AICH acquisition indicators included in high physical downlink shared channels. HS-PDSCH speed in HSPDA (High Speed ​​Downlink Packet Access), where they are shared by several mobile stations and used for transmission of the information (modulation methods, sparse coding, etc.) that is necessary for mobile stations to perform demodulation with respect to shared HS-DSCH high-speed downlink channels , the information that is necessary for error-correcting decoding and HARQ processing, and the wireless resource planning information (frequency, time).

DSDCH downlink shared data channels correspond to HS-DSCH high speed downlink shared channels and DPDCH downlink dedicated data channels included in HS-PDSCH high speed physical downlink shared channels in HSPDA, where they are used for packet data transmission to mobile stations from higher order layers. Multicast / broadcast channels are used for broadcasting information signals. The aforementioned physical channels of W-CDMA and HSDPA are described in "Tachikawa Keiji, W-CDMA Mobile Communication Method, ISBN4-621-04894-5" and the like.

Figure 14 and Figure 15 are tables that describe the relationships between the maximum delay time (n-1) T between transmitting antennas and the frequency bandwidth Fc of segments in connection with physical channels. As shown in the figures, it is preferable to set (n-1) T &lt;1 / Fc independently of the frequency diversity region and the multi-user diversity region with respect to common control pilot channels, common control channels and channels. dedicated control. It is preferable to set (n-1)&gt; 1 / Fc independently of the frequency diversity region and the multi-user diversity region with respect to downlink sync channels. With respect to dedicated pilot channels, it is preferable to set (n-1) T&gt; 1 / Fc in the frequency diversity region and to set (n-1) T &lt;1 / Fc in the multi-user diversity region. Dedicated pilot signals are assumed to be transmitted through transmitting antennas, where the section for imparting delay to delay transmitting signals supplied to n transmitting antennas the maximum delay time (n-1) T or less adjusts the delay time T so that the maximum delay time (n-1) T falls within the range of (n-1) T&gt; 1 / Fc when a communication signal, which indicates whether segments including dedicated pilot channels are subjected to frequency diversity transmission or multi-user diversity transmission, indicates frequency diversity, while adjusting the delay time T to perform directivity control using weights emitted from the section weight calculation or to define the maximum delay time (n-1) T as (n-1) T &lt;1 / F_c when the communication signal indicates multi-user diversity. Multicast / broadcast channels are used in the frequency diversity region only; therefore, it is preferable to set (n-1) T&gt; 1 / Fc.

The reasons for the aforementioned configurations are that the common pilot channels are used for the notification of signal strengths observed by terminals, therefore, it is not desirable that the delay time varies with respect to segments, while it is the wireless transmission device is required to know the signal strengths with respect to segments in case (n-1) T &lt;1 / Fc

ES 2 379 569 T3 in order to realize multi-user diversity, therefore, it is preferable to set (n-1) T &lt;1 / Fc so that the maximum delay time does not vary with respect to segments. The dedicated pilot channels are used for calculations of estimated values ​​of propagation paths used for demodulation of data signals. Therefore, it is preferable to perform the communication by setting (n-1) T&gt; 1 / Fc in the frequency diversity region and setting (n1) T &lt;1 / Fc in the multi-user diversity region.

Downlink synchronization channels are used for frame synchronization, the estimation of propagation paths is not necessary, and it is preferable to guarantee correct reception in case of low reception power; therefore, it is preferable to set (n-1) T&gt; 1 / Fc in order to produce the frequency diversity effect. In particular, there is the possibility that the same signal is transmitted using the same time and frequency through downlink synchronization channels by means of several sectors and several antennas included in a single base station. Therefore, the signals are applied different delays with respect to the antennas and are transmitted by means of several sectors and several antennas included in a single base station through downlink synchronization channels; therefore, it is expected to produce a high frequency diversity effect, which is higher than that of another physical channel.

Common control channels and dedicated control channels are assumed to use estimated propagation path values, which occur via common pilot channels; therefore, it is preferable that they conform to the maximum delay time, which is identical to that of common pilot channels, and are transmitted. However, it is preferable to guarantee correct reception on common control channels and dedicated control channels in case of low reception power; therefore, it is preferable to produce the frequency diversity effect, where, considering the improvement of the reception performance of the control channels first, when common control channels, dedicated control channels and multicast / broadcast channels are included in the same segment, it is preferable to transmit through common pilot channels by setting (n-1) T&gt; 1 / Fc, thus producing the effect of frequency diversity in the control channels.

When using the same segment for multi-user diversity, it is necessary to report on signal strengths emerging in the actual transmission suitable for multi-user diversity (communication according to (n-1) T &lt;1 / Fc); therefore, it is preferable to carry out transmission by setting (n-1) T &lt;1 / Fc. For this reason, it is possible to adjust the relationship between the maximum delay time (n-1) T between transmitting antennas and the frequency bandwidth Fc of the segment, which is identical to the relationship shown in figure 15, with respect to to each physical channel. In order to produce the frequency diversity effect, it is preferable to carry out communication by setting (n1) T&gt; 1 / Fc.

The aforementioned embodiment is described so that the maximum delay time falls within the range of (n-1) T &lt;1 / Fc in the multi-user diversity region, while the wireless transmission device described in the fifth embodiment can use the weight wm, which is produced by the weight calculation section 310, in the multi-user diversity region. The aforementioned second to fifth embodiments are each described such that the wireless transmitting device having n transmitting antennas transmits signals to which a prescribed delay time is applied with respect to each of the n transmitting antennas. ; but this constitution is not restrictive. For example, when the wireless transmitting device having n transmitting antennas selects to use multi-user diversity, it is possible to transmit signals to which a prescribed delay time T 'is applied with respect to each of j transmitting antennas (where j an integer, 1 &lt;j &lt;n) in n transmitting antennas.

In the aforementioned constitution compared to the constitution in which signals are transmitted using all n transmitting antennas, a maximum delay time (j-1) T 'applied to signals transmitted through j transmitting antennas is decreased so that propagation path variations are further reduced; therefore, it is possible to produce a good multi-user diversity effect. In case j = 1, in particular, it is possible to reduce the circuit scale of the delay section. The present embodiment is described with the precondition that the maximum delay time is set as (n-1) T&gt; 1 / Fc in order to produce the effect of frequency diversity, while, as described in the First embodiment, when transmission is performed using a physical channel, to which segments located in various frequency directions are assigned, the BW bandwidth assigned to the physical channel forms the basis for producing the effect of frequency diversity; therefore, it is possible to produce the frequency diversity effect by setting the maximum delay time to (n1) T&gt; 1 / BW.

By using the wireless transmission device, according to the aforementioned embodiments of the present invention, which selects the use of either frequency diversity or multi-user diversity in signal transmission from n transmission antennas to vary delay times applied to signals transmitted through n transmitting antennas based on the selection result; therefore, it is possible to produce the frequency diversity effect or the multi-user diversity effect without being affected by propagation path conditions.

In the aforementioned embodiments, the programs that perform the functions of section 13 of

ES 2 379 569 T3 error correction coding, modulator 14, subcarrier assignment sections 15 and 215, IFFT section 16, parallel-serial conversion section 17, section 18 for imparting GI, sections 19 -1 to 19-3 to impart delay, sections 119-1 to 119-3 to impart flow delay, mix section 20, filter 21, D / A converter 22, phase rotation section 219, The weight calculation section 310 and the weighted multiplication section 319 shown in Figures 8, 10, 12 and 13 are stored on computer-readable storage media, so that the programs stored on the storage media are loaded into a computer system and are then run to control the wireless transmission device. Herein, the computer system includes OS and hardware such as peripheral devices.

Computer-readable recording media are called floppy disks, magneto-optical disks, ROMs, portable media such as CD-ROMs, and storage devices such as hard drives built into the computer system. In addition, computer-readable storage media encompasses media for dynamically retaining programs in a short period of time, such as communication lines such as the Internet, networks, and telephone lines used to transmit programs as well as volatile memories for retaining programs during a prescribed period of time, which are incorporated into the computer system that serves as both server and client. The aforementioned programs are designed to perform a part of the aforementioned functions; alternatively, they are designed to perform the aforementioned functions by combining with programs that are stored in the computer system in advance.

This invention is described in detail by means of the embodiments with reference to the drawings, in which the detailed constitution thereof is not necessarily limited to the embodiments; therefore, it encompasses designs that do not deviate from the scope of this invention as defined by the appended claims.

Industrial applicability

The present invention is applicable to wireless transmission devices and wireless transmission methods, which transmit signals to wireless reception devices through the use of various transmission antennas, wherein delay times are appropriately adjusted based on the determination as to whether the transmission signals are subject to frequency diversity transmission or multi-user diversity transmission; therefore, it is possible to produce frequency diversity effects and multi-user diversity effects without being affected by propagation path conditions.

Description of wireless transmission device reference numbers

2-4 transmitting antenna

5, 6 delay

7, 8, 9, 10 wireless receiving device

11a, 11b, 111a, 111b, 211a, 21b user dependent signal processor

12-1, 12-2, 12-3, 112-1 to 112-3, 212-1 to 212-3, 312-1 to 312-3 Antenna Dependent Signal Processor Modulator Error Correction Coding Section

15, 215 subcarrier assignment section section of IFFT parallel-serial converter section for imparting GI

19-1 to 19-3 section to impart delay

ES 2 379 569 T3 section to impart circulation delay mixer filter converter D / A memory phase rotation section section to impart delay weight calculation section weighted multiplication section section to impart delay and directivity control