Method of operating radio station in cellular communication network

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to communication engineering and can be used in wireless communication systems. The system comprises a plurality of primary stations, each primary station comprising: a transceiver for communicating with a secondary station, said transceiver having two antennae, wherein the method comprises a first one of the plurality of primary stations which transmits to the secondary station for a given spatial channel a first set of reference symbols, and said first one of the plurality of primary stations or second one of said plurality of primary stations transmits to the secondary station for said spatial channel a second set of reference symbols, wherein said at least one second set of reference symbols is orthogonal to said first set of reference symbols, wherein the first and second primary stations receive from the secondary station feedback about the phase difference between the phase of the first set of reference symbols and the phase of the second set of reference symbols received by said at least one secondary station.

EFFECT: high quality of transmitting information.

15 cl, 5 dwg

 

The technical field TO WHICH the INVENTION RELATES

The present invention relates to a cellular network that contains the primary station serving the cell and adapted to communicate with multiple secondary stations located within the cell.

This invention, for example, refers to UMTS or LTE, or any system that uses supporting characters to decode spatial channels. This invention can be advantageously implemented in systems that use beamforming or MIMO.

PRIOR art

Conventional telecommunication system is illustrated in Fig.1. In such a system, the network is structured with a plurality of cells. In each cell, e.g. in cell 101 in Fig.1 the primary station 100 serving cell. This means that the primary station organizes and handles all communications with the secondary stations 110 in the cell. The communication signals are transmitted through different channels. Typically, at least the data channel downlink (from the primary station to a secondary station and a control channel of the descending line are transmitted to the primary station. Similarly, the data channels corresponding to the uplink (from the secondary station to the primary station) and the control channels are also passed, but for clarity of the drawing, these channels opuskayut� in Fig.1.

In the LTE system, for example, the primary station 100 includes multiple antennas, and it is able to regulate the corresponding transmission antenna gain and the phase for the creation of data streams formed of the radiation patterns in the direction of the secondary stations 110. These factors are antenna gain and phase can form the matrix pre-coding (or vector, if there is only one transmission beam). Message alarm management by Physical Control Channel of the Descending line (PDCCH) is used for distribution of signals transmission resources on a custom channel PDSCH. In General, the transmission with shaped radiation pattern can be proposed for transmission over a spatial channel. The reception of the data stream with the generated radiation pattern usually requires phase and possibly the reference signal amplitude at the receiver. Such reference signals may be issued by passing a known reference symbols with the same vector of beamforming, as applied to the data. These reference symbols may be multiplexed with the data or information management, using known methods, such as TDM, FDM or CDM. Therefore, a spatial channel may be determined relative to the reference symbols transmitted using com�Inacio from the set of TDM, CDM, FDM and vector beamforming. To the primary station 100 could plan the transmission of downlink data to make efficient use of system resources, the secondary station 110, it is usually assumed to supply the primary station feedback about the state of the channel downlink, for example, explicit feedback, such a transfer function of the channel power level of interference or the covariance matrix of the interference. It is also possible to have implicit feedback according to the assumption of a particular transmission scheme, such as the preferred rank of transmission, the preferred matrix prior coding or vector(s), or the available data transmission rate (for example, CQI). This feedback is usually based on the observation of periodically transmitted reference symbols, developed for this purpose (i.e., CSI-RS or a Supporting Character Status Indicator Channel), and the estimated interference.

However, in a system like LTE advanced, it is desirable to reduce utility costs due to the transmission of CSI-RS, and therefore, the CSI-RS intended for infrequent transmission.

Summary of the INVENTION

The object of the invention is to propose a method for communication in the network, which alleviates the aforementioned problem.

Another object of the invention is the proposal of the method of delivery�I connected to the network, which allows the secondary station to measure and evaluate the conditions of the channel.

Another object of the invention is the provision of a method for a communication system that allows the secondary station to estimate channel conditions without requiring too much the service costs.

To this end, in accordance with the first aspect of the invention provides a method according to claim 1.

In accordance with the second aspect of the invention provides a method according to claim 12.

In accordance with a third aspect of the invention, it is proposed a primary station according to claim 14.

In accordance with the fourth aspect of the invention, it is proposed a secondary station according to claim 15.

These and other aspects of the invention will become apparent and will be explained with reference to options for implementation, described later.

BRIEF description of the DRAWINGS

The present invention is described below in more detail by example with reference to the accompanying drawings, in which:

Fig.1, already described, is a block diagram of a conventional telecommunication system.

Fig.2 is a block diagram representing a communication system in accordance with the first embodiment of the invention.

Fig.3 is a flowchart representing a method in accordance with the invention.

Fig.4 is a block diagram, predstavlyayushie� loop control phase, formed by the secondary station and a primary station of the first variant implementation.

Fig.5 is a block diagram representing a communication system in accordance with another variant implementation of the invention.

DETAILED description of the INVENTION

The present invention relates to a cellular telecommunication system, such as UMTS or LTE telecommunication system. More specifically, the present invention is based on the understanding that instead of using the reference characters specifically to assess the conditions of the channel, this can be done by modification to specialized reference characters are used in the conventional system to aid in the decoding of the channel downlink data with the generated pattern.

Referring to Fig.1 explained the work of the specialized (dedicated reference symbols (DRS) in a conventional communication system. As seen in the preamble of the present description, the system according to Fig. 1 comprises a primary station 100 operating in the cell 101, which is a lot of secondary stations 110. For clarity, only two secondary station shown in Fig.1. In this example, the system is LTE telecommunications system that uses a single carrier up to 20 MHz. In this example, the primary station 100 transmits sweat�to 111 data with the generated radiation pattern with two antennas 104, where the signals transmitted from the antennas are weighted by the coefficients of the preliminary coding. This example assumes that only two of the four antennas of the primary station 100 is used for this stream data 111.

In conjunction with LTE the primary station probably has at least four antennas, the set of which can be used for a single transmission, as in this example. Similarly, the secondary station has multiple antennas of the reception (e.g. 2, 4 or 8). Message alarm management, transmitted to the primary station 100 via the Physical Control Channel Downlink (PDCCH) is used for distribution of signals transmission resources, and in this example is for the information of signal transmission with the generated pattern.

Alarm vectors/matrices pre-coding PDCCH allows the secondary station to calculate the reference(s) phase for the demodulation of the stream data 111 from a common reference characters. As an alternative mode-specific secondary station Reference Demodulation Symbols (DRS) can be used to aid in receiving downlink data from the primary station. DRS takes some of the resource elements (elements RE) in each resource block containing transmission data to the secondary station. These elements�s resources known secondary station 110 thus, to the secondary station was able to extract these elements RE and decode the supporting characters in them. It should be noted that in the case of a transfer of the second spatial channel to the secondary station 110 will require a set of DRS for each spatial channel.

The set of DRS for the spatial channel 111 can be pre-encoded in the same way as the data for that spatial channel 111, and since the locations and values of the symbol DRS-known secondary station 110, they can be used as a reference phase and amplitude for demodulation of data transmitted on this spatial channel 111. Equivalent, specialized reference symbols can be used to obtain the channel estimation, the combined channel formed by pre-coding, and radio channel. Pre-coding for spatial channel may be considered to create the antenna port, and a set of DRS for that spatial channel is thus transmitted to the appropriate antenna port.

The set of DRS for each spatial channel may differ by one or more of:

- Sequence Modulation: that is a different sequence of preset values for consecutive reference symbols

- H�frequency region (FDM), that is, the elements of the RE used for sending DRS differ in the frequency domain

- Time domain (TDM), i.e. the elements of the RE used for sending DRS differ in the time domain

- Code domain (CDM), that is, different broadening the spectrum of the sequence are applied to the transmitted symbols containing DRS. In this case it would be convenient to use the same set of items RE to make each set of DRS for each spatial channel.

Practically, the DRS for a given spatial channel may include all aspects of: - Sequence Modulation, FDM, TDM and CDM.

It should be noted in this particular example implementation, the maximum number of spatial channels that can be transmitted to the secondary station 110 in a single cell 101, is 8. It should be noted that by itself, this does not limit the total number of spatial channels transmitted in a cell. In addition, the number of Resource Elements for DRS in one Unit of Resources can be a number, such as 12 or 24. In addition, it is assumed that the structure of the DRS should allow some interpolation of the coefficients of the channel for one Resource Block, at least in some circumstances. In accordance with this conventional implementation of a mapping one-to-one between the set of DRS and front�AMI on a single antenna port. To the primary station 100 may manage the transmission of downlink data to make efficient use of system resources, the secondary stations, it is generally assumed, provides the primary station feedback about the state of the channel downlink, as explained in the preamble of the description. As noted above, this feedback may be explicit or implicit, and is usually based on the observation of periodically transmitted reference symbols, developed for this purpose like CSI-RS, together with estimates of interference.

The invention is based on recognition of the fact that if the number of available sets of DRS significantly exceeds the number of spatial channels (i.e., antenna ports) in use at any time, it is possible to associate more than one set of DRS, with a given antenna port in the primary station. If each set of DRS is transmitted using a different set of coefficients pre-coding (i.e., using great virtual antenna), the secondary station may be able to output additional information about the state of the channel, the observed different sets of DRS. Additionally, the secondary station may, therefore, withdraw the reference phase for demodulating the transmission data from the antenna port. Therefore, the secondary station d�should be notified of the algorithm to calculate the phase reference of the received sets of DRS.

As a simple example, consider that the system according to Fig.1 has two antennas (antenna 1, antenna 2) transmission to the primary station. For simplicity, the secondary station, as expected, has a single receiving antenna, but the same principles can be applied to the secondary stations with more than one antenna. The only spatial channel 111 is used to transmit data to the secondary station (i.e. use a single antenna port transmission). Weights of the antenna pre-coding data are w1 and w2.

According to the conventional system of Fig.1, the first set of DRS can be transmitted with a weight w1 from the antenna 1 and also must be passed with a weight w2 from the antenna 2. If the coefficients of the channel from the transmit antennas to the receive antennas are h1 and h2, the secondary station 110 may output the reference phase for the data from the combined received signals from the two transmit antennas, which can be specified by d1(w1.h1+w2.h2), where d1 is a supporting character. Since d1 is known, the estimation of the channel is determined by (w1.h1+w2.h2), and it can be used as a phase reference.

According to the first embodiment of the invention, transmitted two sets of DRS. The first set of DRS d1 is transmitted using the weight w1 from the antenna 1, and the second set of DRS d2 is transmitted, using the weight w2 �t antenna 2.

Then, the signal is adopted at the secondary station, is equal to (d1.w1.h1+d2.w2.h2). Assuming that d1 and d2 are orthogonal, and they are known secondary station, both of w1.h1 and w2.h2 can be obtained independently. Additionally, can also be obtained by channel estimation and phase binding equivalent to that required in the conventional system (w1.h1 + w2.h2).

This first variant of the implementation shown in Fig.2. Telecommunication system according to Fig.2 contains the primary station 200 operating in the cell 201, which is a lot of secondary stations 210. For the sake of clarity, only two secondary station 210 shown in Fig.2. The primary station 200 includes multiple antennas 204 transmission, driven unit 205 pre-coding, which can adjust the gain and phase of the transmission antennas for transmission mode beamforming for spatial channels. Chart 211 orientation data shown in Fig.2 from the primary station 200 to the secondary station 210. This chart 211 orientation data, forming a spatial channel may be transmitted on the data channel, such as PDSCH (Physical shared channel Downlink). The secondary station may be informed by the physical layer signaling (e.g., PDCCH or a Physical control Channel of Nished�ing line) spatial channel (i.e., virtual antennas), used for data transmission carried on PDSCH. In addition, the secondary station 210 may be notified by a higher signaling from the primary station 200, which sets the DRS should be used, and what sets DRS associated with the spatial channel 211. In an embodiment of the invention, the number of antennas downlink obviously not reported secondary station that outputs the number of antennas downlink available in the cell, and sets the DRS that are potentially available. As an example, if the schema of the transmission (such as transmission with diversity) used for the control channel depends on the number of transmission antennas, the secondary station may attempt to decode the control channel according to different hypotheses regarding the number of antennas. With appropriate design of the system the correct decoding will take place only when you select the correct hypothesis on the number of antennas.

Spatial channel 211 is obtained in the present description the combination of two component signals 211a and 211b. These signals 211a and 211b include each matching set of DRS, which are orthogonal to each other. Thus, the secondary station 210 may, therefore, assess the product pre-coding and channel conditions� for each of the antennas 204a or 204b transmission, respectively, namely, w1.h1 and w2.h2, as explained above. Indeed, provided that the corresponding sets of specialized reference symbols are orthogonal to each other, to a secondary station may independently evaluate the received signals corresponding to the reference signals of the two component signals 211a and 211b.

Referring to Fig.3 explains the method, implemented in a first embodiment of the invention. In step 300 the primary station 200 transmits component signals 211a and 211b with their respective sets of reference signals. To achieve this, the primary station 200 applies the pre-coding to data that is transmitted using the spatial channel, and applies appropriate pre-coding to the respective sets of DRS so that the secondary station is able to receive the phase reference in accordance with the signaled an algorithm or a predetermined algorithm. An example of a suitable algorithm for a system with one set of DRS for the spatial channel can be designed for finding the values of a complex constant, which when multiplied by a signal representing a known or accepted transfer of DRS, gives the minimum mean square error relative to the received signal transmission. This constant can then be OTS�ncoi transfer function of the channel. It can be used to provide phase reference for demodulation of data at the appropriate spatial channel. In a system with two DRS for a single spatial channel corresponding algorithm may be to use a phase reference based on the average of the two estimates of the channel received from each of the relevant DRS. The component signals 211a and 211b formed spatial channel 211. In step 301, the secondary station 210 accepts component signals 211a and 211b. The secondary station 210 (logically) outputs the channel estimation corresponding to the accepted reference symbols signals 211a and 211b in step 302, and (logically) displays the phase reference from these estimates of the channel in step 303 by means of the algorithm. In one embodiment, the secondary station 210 is informed by signaling a higher level algorithm that should be applied for obtaining a phase reference for each spatial channel of the received sets of DRS. Example of selection algorithms, signaling a higher level indicates that the phase reference must be withdrawn or the sum of the estimated channel, or from the difference between the estimated channel. In this example there is only a single spatial channel, but the same applies to the multiple spatial channels. The secondary station 21 are also able to make measurements of the received phase of each set of DRS (relative to the same set, which is used as a reference) in step 304. Phase measurement is then quantized and are signaled in the message 215 signaling to the primary station 200 in step 305. The primary station can use these measurements to Refine the preliminary coding stage 306.

In a variant of this first embodiment of the secondary station provides more detailed feedback channel state information to the primary station in addition to or instead of the measurement phase. For example, the feedback may include known parameters such as CQI (quality Indicator channel), or the amplitude information, such as average amplitude, or difference of amplitudes.

Regarding the transmission of sets of Reference Symbols for a secondary station, it is preferable that no data is sent (for any spatial channel) in any Element of the Resources used for DRS. This avoids any interference between the data and the DRS that otherwise reduce the accuracy of the channel estimation obtained by the secondary station. For FDM, TDM and CDM assumes that the resource elements used for any DRS, data is not available for any spatial channel.

In principle, the maximum number of spatial channels that can be supported for a single Resource Block, equal to the total number of elements stored� resources assigned to DRS. In practice, this maximum number may be set at a lower level, for example, so that the total number of Resource Elements distributed on DRS, amounted to a multiple of the number of the maximum number of allowed spatial channels. The number of elements RE, distributed to DRS, may be proportional to the number of spatial channels is actually transferred to the second station. This is applicable for FDM or TDM, and has the advantage of reducing utility costs from DRS when transmitted less spatial channels than the maximum.

The number of resource elements allocated for DRS, can be fixed (for example, as a multiple of the maximum number of spatial channels that can be transmitted to the UE). It can be seen as a natural consequence of the use of CDM. For FDM and TDM, and CDM is also allowed different spatial channels to be transmitted simultaneously to more than one secondary station. It is required that the secondary station knew what sets DRS should be used as a reference for the reception of their data (and what DRS correspond to which part of the data stream). This can be indicated explicitly through signaling, such as indicating a mapping between DRS and spatial channels, or �eave, for example, a fixed display, depending on the number of spatial channels transmitted.

The number of resource elements allocated for DRS, may be different, regardless of the number of spatial channels. This will allow more or less a supporting character to use for a given spatial channel depending on priority, whether a particular transmission (for example, a modulation scheme, such as 16QAM or 64QAM) for a specific channel (for example, high or low speed mobility) of more accurate channel estimation, which is possible with a large number of supporting characters. This advantage must be balanced with the loss in data rate from increased utility costs transfer more of the supporting characters.

It should be noted that the secondary station at the cell border can accommodate DRS from more than one cell, from neighboring cells of the cell 201. In this case, it is advantageous to control the system so that the same timing of frames used in the adjacent cells, and also so that DRS from different cells could be different (for example, through a different Sequence of Modulation/FDM/TDM/CDM). If the secondary station is able to identify different DRS from different cells and have multiple �nanny reception there are at least the following features:

- Receiving secondary station 210 data transmission from the cell 201 and the adjustment of weights for the deviation of the spatial channels from other cells.

- The simultaneous admission of the secondary station 210 data transmissions from the cell 201 and at least another cell (using different spatial channels and different DRS).

In one embodiment, there is a special advantage for the secondary station 210 to be able to distinguish DRS from different cells using different sequences of modulation, as it will not increase the number of resource elements required for DRS. However, the performance of this approach may be lower with rapidly changing channels.

In an embodiment of the first variant of implementation, continuing with the example in Fig.2, the transmission is designed for install of equal power from each antenna transmission such that w1 and w2 have the same value. In this case, the maximization of the received SNR can be achieved by selecting the proper phase for w2 relative to w1, that is, to maximize (w1.h1+w2.h2). In this case, the goal is to make the phase w2.h2 is equal to the phase w1.h1. As mentioned previously, according to the first embodiment of the invention, the secondary station can output as w1.h1 and w2.h2 from the corresponding orthogonalization DRS. Although according to these assumptions the secondary station cannot easily get w1, h1, w2 or h2 individually, one can easily calculate the phase difference between w1.h1 and w2.h2 and pass on feedback (for example, in quantized form to the primary station in step 305). This information is required primary station 200 to make any necessary adjustment to the phase difference between the transmitter w1 and w2 in step 306.

In variations of this example, the quantization and alarm measurements phase phase 305 uses one bit to indicate whether the phase is too high or too low (i.e. positive or negative). Thus, it permits the creation of a kind of loop (loop) control so that the primary station was able to adjust the pre-coded spatial channel by means of assessments. In addition, the alarm, being limited by one bit in this example, avoids using too many resources. It should be noted that can be used more than one bit to have two team size phase transmission phase by the feedback. For example, the quantization of the measurement phase can use two bits, one bit to indicate whether the phase is positive or negative, and another bit to indicate the amplitude of the phase.

In the implementation of this option� the implementation of the quantization of the phase measurements transmitted by adapting an existing signaling channel uplink (for example, replacing bits of the PMI and/or RI, with measurements of phase).

Fig.4 schematic image represents the control loop phase formed by the primary station and secondary station. In line with this approach, the primary station 200 may be considered as a block 4200, receiving the difference signal from 4215 secondary station forming a block 4210, which adopts a spatial channel 4211. Of these reference signals in the spatial channel 4211 generated signals 4211a and 4211b, block 4210 secondary station estimates the phase difference in accordance with the algorithm. This difference 422 phases is compared with a target of 430 phase difference, which is zero in this example. A value of zero maximizes the signal quality (SNR) or throughput. This task 430 phase binding is compared in block 431 of the comparison in block 4210 of the secondary station with a difference of 422 phases. The result of this comparison is quantized in block 432 quantization and transmitted as a signal on the block 4215 4200 primary station. The primary station 4200 adjusts its weights pre-coding on the basis of a received signal 4215 for spatial transmission channel 4211.

In variations of the above-mentioned first control circuit feedback (to a predefined number of estimates) specified by the secondary station that contains the full indicator �atrice preliminary preferred encoding of the vector pre-coding (or matrix pre-encoding transfer grade, which is more than 1). Then, the primary station may use this feedback in the vector pre-coding (or other vector pre-coding depending on other gear) to send data. After a predefined number of evaluations feedback transmitted by the secondary station may take the form of one or two bits of the command phase.

In another example of this variant, the value of w1 can be fixed (e.g., with zero phase). This effectively makes the antenna 1 support. The same approach can be extended in the case when the secondary station receives the transmission from more than one antenna port. In this case, the physical antenna can transmit more than one set of DRS at the same time. Therefore, the desired property of sets of DRS is that the sum of the signals corresponding to each weighted set of DRS, gives a combined signal, which essentially has a constant amplitude.

As a simple example problem for the case of CDM, consider a possible sequence of expansion of the spectrum DRS (1,1). The second orthogonal sequence of expansion of the spectrum can be (1,-1). However, if a modulation symbol for both DRS is set to 1, and is multiplied by a sequence of expansion of the spectrum, and these two signals are summed together, �esultats is (2,0). Thus, if the transfer takes place at the same time, requires double the power for determining the first symbol and zero power for the second. Equal amplitude can be achieved by appropriate construction from DRS. For example, if the second sequence DRS will be (j,-j), the sum of the first and second sequences will be (1+j, 1-j).

However, different sets of DRS probably have different coefficients applied pre-coding, thus, the condition of the same amplitude may not always respected. To address this, it is proposed to assign specific sets of DRS on specific spatial channels, striving for constant amplitude under the assumption that the used pre-coding. It is also possible that DRS are not pre-coded. Then the primary station transmits additional information (for example, the coefficients of the pre-encoding), which detects, as a phase reference must be obtained from DRS. This requires a separate alarm algorithm for the evaluation phase binding DRS. In another example, previously encoded reference symbols, but some sets DRS have alternation (rotation) of the phases used to achieve constant amplitude.

In another example, previously encoded reference symbols n� some sets DRS have the phase sequence, used to achieve essentially equal amplitudes for transmission of combined DRS from each antenna transmission. To the secondary station was able to receive data transmitted over a corresponding spatial channels, where some DRS have phase, alternating with other DRS, the phase sequence must be known at the secondary station.

In a variant implementation, which convey more than one spatial channel with one or more sets of DRS for each spatial channel transmitted using the CDM, can be achieved essentially equal amplitude for the combined transmission of DRS from each antenna transmission, applying the phase rotation to the DRS for a given spatial channel. Therefore, the primary station when transmitting a DRS using CDM, should be able to choose the phase rotation to be applied to the set or sets of DRS corresponding to the specified spatial channel to achieve a good balance of power among the transmission antennas, and transmitting the combined signal DSR. The phase sequence can be selected, considering the pre-coding applied to each spatial channel, and should also be applied to the appropriate set of DRS. The same phase must be applied to data transmitted over a corresponding spatial Cana�. This is equivalent to applying the phase rotation to the coefficients of a pre-coding for a given spatial channel to adjust or control the transmission power of the combined DRS from each antenna transmission in the elements RE, containing DRS. This alternation of phases can be freely selected primary station, as is equal to the phase sequence is applied to all elements of the vector pre-coding does not alter the radiation pattern. Preferably identical coefficients pre-coding (including any phase) should be applied to DRS and to data.

Another approach is for some characteristics that differ in a known manner, to avoid the recurrence nonconstant amplitude (for example, apply phase dependence on frequency or time). This can be achieved with different pseudo random sequence modulation for each spatial channel.

In variations of the first embodiment of the algorithm to produce (output) the phase reference for the spatial channel is fixed and contains the summation of composite channel estimates obtained from each DRS associated with this spatial channel. This means that the algorithm is� simply the sum of the values of w1.h1 and w2.h2 in the example of the first embodiment of the phase and the binding is obtained from this result.

In an additional variation of the first embodiment of the algorithm to obtain the phase reference for the spatial channel is the summation of the channel estimates obtained from each of the DRS associated with this spatial channel, wherein each channel estimation is applied, the phase sequence, which is signaled by the primary station. Indeed, the primary station applies the appropriate phase to each transferred to DRS. For example, if the phase sequence is applied to one antenna, for example the alternation of α to the antenna 2, the algorithm needs to summarize phase w1.h1 and w2.h2 and subtract α to obtain the result or as summarized in the equation below:

ΔPhase = φ(w1.h1) + φ(w2.h2) - α

In an additional variation of the first embodiment of the algorithm for deriving a phase reference for the spatial channel should summarize the channel estimation obtained from each of the DRS associated with this spatial channel, where each channel estimation is applied, the phase sequence, which depends on the frequency (for example, the resource block or sub-carriers) and/or time (e.g., number podagra). The primary station applies the appropriate phase to each transferred to DRS. As an example, the value of α in the previous variation is a function of frequency.

In the first embodiment �of sushestvennee only one spatial channel is transmitted to the secondary station 210. The same applies to more than one spatial channel transmitted to the secondary station. In this case, the respective sets of reference symbols are allocated to each spatial channel. The sets of DRS for the first spatial channel being orthogonal to each other, can be selected and/or pre-encoded to be orthogonal to the sets of DRS for the second spatial channel.

In additional variations of the primary station has N physical antennas (e.g., N=2), and one set of DRS is transmitted for each physical antenna.

The second variant of implementation otherwise similar to the first variant of implementation, but the secondary station also measures the amplitude of one or more of the DRS and reports them to the primary station. This allows the primary station to decide on the appropriate transmission mode, for example to allocate more or less power for transmission from a particular antenna (e.g., a corresponding one of the sets of DRS).

Fig.5 illustrates a third embodiment of the invention. Telecommunication system of Fig.5 contains the primary station 500a operating in the first cell 501a, which is a lot of secondary stations 210. The adjacent cell 501b is controlled by a primary station 500b. In a variant of this option osushestvlenie cell 500a and the second cell 501b managed by the same primary station. For the sake of clarity, only two secondary station 510 shown in Fig.5. The primary station 500a and 500b comprise a plurality of antennas 504a and 504b transmission, respectively-managed units 505a and 505b pre-coding, which can adjust the gain and phase of the transmission antennas for transmission mode beamforming for spatial channels. Beam 511 data shown in Fig.5 from the primary stations 500a and 500b to the secondary station 510. These directional patterns 511 data forming a spatial channel may be transmitted over a data channel, such as PDSCH (shared Physical channel Downlink). Spatial channel 511 in the present description is obtained from the combination of two component signals 511a and 511b, respectively transmitted to the primary station 500a and 500b. These signals 511a and 511b include an appropriate set of DRS, which are orthogonal to each other. Thus, the secondary station 510 can thus assess the product pre-coding and channel conditions for each antenna 504a or 504b transmission, respectively, namely w1.h1 and w2.h2, as explained above. Indeed, provided that the corresponding sets of specialized reference symbols are orthogonal to each other for a secondary station, in�you can independently evaluate the received signals, the corresponding reference signals of the two component signals 511a and 511b.

As in the first variant of implementation, the secondary station can be informed through signaling of the physical layer (e.g., PDCCH or a Physical Control channel of the Descending line) spatial channel (i.e., virtual antennas used for data transmission carried on PDSCH. In addition, the secondary station 510 can be informed by a higher signaling from the primary station 500a and/or from the primary station 500b, what sets DRS will be used, and what sets DRS associated with the spatial channel 511. In a variant of this embodiment of the number of antennas downlink explicitly signaled secondary station that outputs the number of antennas downlink available in the cell, and sets the DRS that are potentially available. As an example, if the transmission scheme (such as a diversity transmission) used for the control channel depends on the number of transmission antennas, the secondary station may attempt to decode a control channel according to different hypotheses regarding the number of antennas. With the corresponding structure of the system the correct decoding will take place only when the correct hypothesis regarding kolichestvennom was selected.

As a consequence, the third variant of implementation otherwise similar to the first variant of implementation with a single spatial channel transmitted to the secondary station, but it consists of identical data transmissions from two (or more) of cells (or access points). Transmission from each cell associated with a different set of DRS (for example, one set of DRS for each cell). The phase reference for reception and transmission of data was derived by summing the estimates of the channel from each of the sets of DRS.

The fourth variant embodiment of the invention similar to the first variant implementation, where the primary station can transmit one or two spatial channel to the secondary station. In the case of two spatial channels (i.e., a rank 2 transmission with 2 phrases) the primary station transmits two sets of DRS, one for each spatial channel. The secondary station receives two sets of DRS and can output the corresponding phase reference for the appointment of two spatial channels (two keywords). The right (or opposite) of each keyword is designated secondary station sending two acks/NACK via PUCCH (Physical Control channel of Upward communication line). In the case of one spatial channel (i.e., a rank 1 transmission) the primary station also transmits two sets DR, one for each of the two antennas or virtual antennas. The secondary station combines two adopted DRS for the formation of single phase binding for receiving a single keyword. The right (or opposite) of the keywords is indicated by sending the ACK/NACK via PUCCH. Another available ACK/NACK is accepted only bit quantized phase information indicating the phase difference between two phase bindings (or channel estimates, each derived from one of the accepted sets of DRS. The primary station may use this information to improve pre-coding/beamforming applied to subsequent transmissions of a single keyword.

The present invention should be considered not only according to the above implementation options, specialists in the art it will be understood that the above-mentioned options and examples can be combined and adapted in various implementations of the invention.

The invention applies to systems using joint beamforming between cells, which may include LTE advanced. The cell may be located in a single cell with a base station or in different cells, such as Femto-cells, sold for� methods of fiber optics.

In the present description and the claims mention only the number preceding the element does not exclude the presence of many such elements. Additionally, the word "contains" does not exclude other elements or steps than those listed.

The inclusion of a reference position in parentheses in the claims is meant to help understand and is not intended to limit.

From reading this description, other modifications will be obvious to those skilled in the art. Such modifications may involve other features which already known in the art of radio communications.

1. A method of operating a plurality of primary stations (200, 500) for mobile communication, with each primary station comprises: a transceiver for communicating with at least one secondary station (210, 510), over and above the transceiver includes at least two antennas (a, 204b, 504a, 504b), wherein the method comprises a first one of the plurality of primary stations broadcasting on the mentioned at least one secondary station for a given spatial channel (211, 511) of the first set of reference symbols with a first vector of pre-encoding applied before transmission, and mentioned the first one of the plurality of primary stations, or the second one referred to a VA�TBA primary stations transmits to the secondary station for the spatial channel, at least one second set of reference symbols with a corresponding second vector of pre-encoding, applied before transmission, and mentioned at least one second set of reference symbols is orthogonal to the first set of reference symbols,
at least one of the first and second primary stations receives from the at least one secondary station, the feedback information regarding the phase difference between the phase referred to the first set of reference symbols and a phase of at least one of the at least one second set of reference symbols adopted by the mentioned at least one secondary station.

2. A method according to claim 1, wherein the first primary station and/or the second primary station uses the feedback information to modify the first vector pre-coding and/or second vector pre-coding, respectively.

3. A method according to claim 1 or 2, further comprising issuing from the primary station to a secondary station identifier of at least one of the first and second sets of reference symbols.

4. Method according to any one of claims. 1 or 2, wherein at least one of the first vector pre-encoding and the second vector of pre-encoding is such that only one element of the vector pre-coding has a value other than zero.

5. �p on p. 4, in which the phase of the first element of the first vector pre-coding is equal to zero.

6. Method according to any one of claims. 1 or 2, further comprising the primary station transmitting to a secondary station for another single spatial channel of the third set of reference symbols with a third vector of pre-encoding applied before transmission and at least one fourth set of reference symbols with a corresponding fourth vector of pre-encoding applied before transmission, and the third set of reference symbols is orthogonal to the first mentioned at least one second and at least one fourth sets of reference symbols and at least one fourth set of reference symbols is orthogonal to the first and at least one second set of reference symbols.

7. Method according to any one of claims. 1 or 2, wherein the first and second sets of reference symbols are arranged so that the signal obtained from the sum of the first set of reference symbols, pre-encoded by the first vector of pre-encoding, and the second set of reference symbols, pre-encoded by the second vector pre-coding, had a constant amplitude.

8. A method according to claim 6, wherein the first and�ora sets the reference symbols are configured so as to the signal obtained from the sum of the first set of reference symbols, pre-encoded by the first vector of pre-encoding, and the second set of reference symbols, pre-encoded by the second vector pre-coding, had a constant amplitude, and in which the third vector of pre-encoding is equal to the first vector of pre-encoding and the fourth vector of pre-coding equal to the second vector pre-encoding.

9. A method according to claim 7, in which the primary station applies a phase rotation to at least one of the first or second sets of reference symbols so that the signal obtained from the sum of the first set of reference symbols, pre-encoded by the first vector of pre-encoding, and the second set of reference symbols, pre-encoded by the second vector pre-coding, had a constant amplitude according to transmission antennas.

10. A method according to claim 9, in which the primary station signals applied to the phase rotation to the secondary station.

11. Method according to any one of claims. 1 or 2, further comprising at least one of the plurality of primary stations, for transmitting additional single spatial channel a third set of reference symbols � the third vector of pre-encoding, applied before transmission and at least one fourth set of reference symbols with a corresponding fourth vector of pre-encoding applied before transmission, wherein the primary station applies the alternating third and fourth vectors pre-coding, so that the power level was the same for each transmission antenna.

12. A method of operating a secondary station (201, 501) for mobile communication, wherein the secondary station comprises a transceiver for communicating with at least first one of the plurality of primary stations (200, 500), the method contains the secondary station receiving from the first one of the plurality of primary stations for a given spatial channel (211, 511) of the first set of reference symbols and the host mentioned the first one of the plurality of primary stations, or from a second one of said plurality of primary stations for the spatial channel, at least one second set of reference symbols, moreover, the aforementioned at least one second set of reference symbols is orthogonal to the first set of reference symbols, and the secondary station that computes the feedback information corresponding to the phase difference between the phase of the received first set of reference symbols and a phase of at least about�tion from a received at least one second set of reference symbols, moreover, the secondary station transmits the feedback information on the first primary station and/or the second primary station.

13. A method according to claim 12, wherein the calculation of said information feedback includes a secondary station, making channel estimation for each of the first and second sets of reference symbols.

14. The primary station (200, 500) for a mobile station that contains a transceiver for communication with at least one secondary station (210, 510), over and above the transceiver includes at least two antennas (a, 204b, 504a, 504b), wherein said primary station is adapted to transmit the mentioned at least one secondary station for a given spatial channel (211, 511) of the first set of reference symbols with a first vector of pre-encoding applied before transmission, and at least one second set of reference symbols with a corresponding second vector of pre-encoding applied before transmission, and mentioned at least one second set of reference symbols mentioned is orthogonal to the first set of reference symbols, wherein said primary station is adapted for receiving from the at least one secondary station, the feedback information regarding the phase difference between patiopatio first set of reference symbols and a phase of at least one of the at least one second set of reference symbols, taken mentioned at least one secondary station.

15. The secondary station (210, 510) for mobile communication, containing a transceiver for communication with at least first one of the plurality of primary stations (200, 500), wherein the transceiver is adapted to receive from the said first one of said plurality of primary stations for a given spatial channel (211, 511) of the first set of reference symbols and receive from the said first one of said plurality of primary stations, or from a second one of said plurality of primary stations for the spatial channel of the at least one second set of reference symbols, moreover, the aforementioned at least one second set of reference symbols is orthogonal to the first set of reference symbols and the secondary station is adapted to calculate the feedback information corresponding to the phase difference between the phase of the received first set of reference symbols and a phase of at least one of the received at least one second set of reference symbols, wherein the secondary station is adapted to transmit feedback information to the first primary station and/or the second primary station.



 

Same patents:

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to network communication, such as mobile communication. The invention particularly discloses a method for communication over a network, which comprises a first cell and a second cell respectively including a first primary station having a first antenna array dedicated to the first cell and a second primary station having a second antenna array dedicated to the second cell, for communicating with a plurality of secondary stations, the method comprising a step of providing cooperative beamforming transmission from the first and second primary stations to at least one first secondary station, the step including: first secondary station signalling at least one channel matrix to at least one of the first and second primary stations, and the first and second primary stations applying a precoding matrix to both the first antenna array and the second antenna array, and wherein the precoding matrix comprises a first vector for the first cell and a second vector for the second cell, the precoding matrix being based on the at least one channel matrix.

EFFECT: providing codebooks which can be used for beamforming.

14 cl, 2 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to communication engineering and can be used in mobile communication systems. The method includes determining a transmission rank for downlink transmission to a user terminal; determining one or more reference signal antenna ports for said downlink transmission based on said transmission rank, wherein each port is defined by an group/code pair comprising a code division multiplexing group and orthogonal security code; mapping reference signal antenna ports to group/code pairs for each transmission rank such that the code division multiplexing group and code orthogonal security code are the same for a given antenna port for every transmission rank; and transmitting downlink check symbols through said reference signal antenna ports according to the transmission rank.

EFFECT: high reliability of transmitting information using antenna port mapping for demodulating reference signals.

16 cl, 1 tbl, 7 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to transmitting and receiving data using multiple frequencies. Measurement of communication quality using a broadband signal and transmission and reception of data using a predetermined frequency band is carried out at approximately the same time. The transmitting device (1) is capable of transmitting data at a first frequency and a second frequency to a receiving device (2). The transmitter (1a) of the transmitting device (1) transmits a predetermined broadband signal in a first period of time in a frequency band which does not include the first frequency, and in a second period of time in a frequency band which does not include the second frequency. The quality measuring unit (2a) of the receiving device (2) measures quality of communication with the transmitting device (1) based on the broadband signal received in the first and second periods of time.

EFFECT: preventing quality degradation when transmitting and receiving data.

21 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to transmitting and receiving data using multiple frequencies. Measurement of communication quality using a broadband signal and transmission and reception of data using a predetermined frequency band are carried out at approximately the same time. The transmitting device (1) is capable of transmitting data at a first frequency and a second frequency to a receiving device (2). The transmitter (1a) of the transmitting device (1) transmits a predetermined broadband signal in a first period of time in a frequency band which does not include the first frequency, and in a second period of time in a frequency band which does not include the second frequency. The quality measuring unit (2a) of the receiving device (2) measures quality of communication with the transmitting device (1) based on the broadband signal received in the first and second periods of time.

EFFECT: preventing quality degradation when transmitting and receiving data.

3 cl, 21 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication and more specifically to sounding feedback transmission in very high throughput (VHT) wireless systems. Sounding feedback may be transmitted from a user station (STA), wherein the feedback may comprise a certain number of beam-forming matrices and a certain number of singular values of a wireless channel associated with the STA. Further, the sounding feedback may comprise a bit for indicating whether said feedback represents a single-user (SU) feedback or a multi-user (MU) feedback.

EFFECT: improved communication.

35 cl, 10 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication systems and is intended to improve user equipment (UE) channel state information (CSI) feedback due to that a precoder part of a CSI feedback report contains factorised precoder feedback. In one or more such embodiments, the factorised precoder feedback corresponds to at least two precoder matrices, including a recommended "conversion" precoder matrix and a recommended "tuning" precoder matrix. The recommended conversion precoder matrix restricts the number of channel dimensions considered by the recommended tuning precoder matrix and, in turn, the recommended tuning precoder matrix matches the recommended precoder matrix to an effective channel that is defined in part by said recommended conversion precoder matrix.

EFFECT: improving user equipment channel state information feedback.

42 cl, 7 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication systems, more specifically to communication between a primary station and one or more secondary stations in a multiple input and, multiple output mode. The method comprises a step where the primary station transmits to the first secondary station an indication of an integration matrix during reception, which the first secondary station must use when integrating signals received at the said plurality of antennae thereof from the first subsequent transmission from the primary station.

EFFECT: improved communication.

13 cl, 2 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication. A method and a device for data transmission based on the interrelation between the first and the second channel are shown. The method might involve measuring the first channel, which corresponds to the first antenna of a wireless terminal, as well as measuring the second channel, which corresponds to the second antenna of the said terminal. The method might also involve the determination of the interrelation between the first and the second channels based on measuring both of them. The method may also involve transmitting the data related to the upperlink transmission. And the said data might be based upon the said interrelation.

EFFECT: demand of UE in order to promote the decision making based upon some measurements of the signals received by multiple antennas at a UE side.

20 cl, 5 dwg

FIELD: radio engineering, communication.

SUBSTANCE: methods and devices are provided wherein user equipment transmits using at least two uplink transmit antennae and receives a set of control signals in the downlink direction from a cellular network. The user equipment estimates a received signal quality for each control signal in said set of control signals and determines, based on said received signal quality, which control signals that have been reliably received. The user equipment derives one or more parameters related to the uplink transmit diversity operation using a subset of control signals from the set of control signals. Said subset only includes control signals determined as reliably received and transmits in the uplink direction applying the derived one or more parameters to control the uplink transmit diversity operation.

EFFECT: invention improves the accuracy of the transmit diversity parameter values derived/set by the UE, which enhances the performance of the uplink transmit diversity and also reduces interference in neighbour cells.

32 cl, 4 dwg

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to wireless communication systems. A re-entry method includes steps of receiving, by a base station of a wireless communication network, a message from a mobile station which includes an indication that the mobile station is in coverage loss recovery mode, and a mobile station identifier to identify the mobile station. The method further includes a step of determining whether a static context and/or a dynamic context associated with the mobile station identifier is stored at a previous serving base station of the mobile station and transmitting a message to the mobile station to indicate which re-entry actions are to be performed to facilitate re-entry of the mobile station into the wireless communication network.

EFFECT: simple procedure of re-entry into a network.

26 cl, 7 dwg

FIELD: mobile communications.

SUBSTANCE: proposed distributed system of intelligent antennas has N antennas, N radio-frequency transceivers, main frequency band digital signal processor in base station of wireless communication system, feeders, and data bus; N antennas and N radio-frequency transceivers are grouped to obtain a number of radio-frequency transceiver groups disposed at different consistent-reception locations of base station, including different buildings or different floors of one building.

EFFECT: improved consistency of reception.

12 cl, 4 dwg

FIELD: communication systems with distributed transmission, in particular, method and device for non-zero complex weighing and space-time encoding of signals for transmission by multiple antennas.

SUBSTANCE: method and device provide for expansion of space-time block code N×N' to space-time block code M×M', where M>N, with utilization of leap-like alternation of symbols phase in space-time block code N×N', to make it possible to transfer space-time block code from distributed antennas in amount, exceeding N'.

EFFECT: distribution of transmission from more than two antennas.

2 cl, 16 dwg

FIELD: automatic adaptive high frequency packet radio communications.

SUBSTANCE: each high frequency ground station contains at least one additional high frequency receiver for "surface to surface" communication and at least one additional "surface to surface" demodulator of one-tone multi-positional phase-manipulated signal, output of which is connected to additional information input of high frequency controller of ground station, and input is connected to output of additional high frequency "surface to surface" receiver, information input of which is connected to common high frequency receiving antenna, while control input is connected to additional control output of high frequency controller of ground station.

EFFECT: prevented disconnection from "air to surface" data exchange system of technically operable high frequency ground stations which became inaccessible for ground communications sub-system for due to various reasons, and also provision of possible connection to high frequency "air to surface" data exchange system of high frequency ground stations, having no access to ground communication network due to absence of ground communication infrastructure at remote locations, where these high frequency ground stations are positioned.

2 cl, 12 dwg, 2 tbl

FIELD: radio engineering, in particular, signal transfer method (variants) and device for realization thereof (variants), possible use, for example, in cellular radio communication systems during transmission of information signal in direct communication channel from backbone station to mobile station.

SUBSTANCE: technical result is achieved due to correction of spectrum of copies of information signal being transferred, transferring copies of information signal from each adaptive antenna array in each effective transmission direction, estimating transfer functions of direction transmission channels on basis of pilot signals transferred from each antenna element, on basis of pilot signals for distributed transmission, sent from each adaptive antenna array in each one of effective transmission directions, and also combining two given estimates.

EFFECT: increased efficiency of transmission of information signal in direct communication channel, and, therefore, maximized quality of receipt of information signal at mobile station.

5 cl, 10 dwg

FIELD: wireless communication receivers-transmitters and, in particular, wireless communication receivers-transmitters which use a multi-beam antenna system.

SUBSTANCE: when controlling a multi-beam antenna system for a downstream line of wireless communications, generation of polar pattern and signaling of distribution during transmission in closed contour are combined, each beam signal is adjusted at transmitter on basis of check connection from wireless communication mobile station in such a way, that signals received by wireless communication mobile station may be coherently combined.

EFFECT: increased traffic capacity and productivity of the system, improved power consumption, cell coverage and communication line quality characteristics.

2 cl, 5 dwg

FIELD: method for estimating a channel in straight direction in radio communication systems.

SUBSTANCE: in accordance to the method, in straight direction, beam is created by a set of antennas, and at least one vector is created for beam generation, subject to application for connection of at least one base station to at least one mobile station, is defined by at least one client station and from at least one client station to at least one base station information is transmitted, which contains information about aforementioned at least one beam generation vector. In accordance to the invention, at least one base station transmits information about beam generation vector used for connection of at least one base station to at least one client station, to at least one client station, on basis of which at least one client station estimates the channel.

EFFECT: transmission of information about beam generation vector due to selection and transmission of pilot-signal series.

2 cl, 2 dwg

FIELD: physics, communications.

SUBSTANCE: invention concerns data transfer, particularly frequency-time-space block coding in a transmitter with three transmitting Tx antennae. Input symbol sequence is transferred by three Tx antennae according to permutation method via selected transmission matrix.

EFFECT: increased data transfer speed.

28 cl, 10 dwg

FIELD: physics; communications.

SUBSTANCE: present invention pertains to communication techniques. The transmitting object carries out spatial processing using control matrices, so that data transmission is held in a set of "effective" channels, formed on the real channel used for transmitting data, and control matrices, used for PRTS. Control matrices can be formed by sampling a base matrix, which can be a Walsh or Fourier matrix. Different combinations of scalars are then chosen, each combination of which consists of at least one scalar, of at least row of the base matrix. Each scalar can be a real or complex value. Different control matrices are formed by multiplying the base matrix by each of the different combinations of scalars. Control matrices are different transpositions of the base matrix.

EFFECT: generation and use of control matrices for pseudorandom transmission control (PRTS).

55 cl, 3 dwg, 1 tbl

FIELD: physics.

SUBSTANCE: invention is related to device and method for beams shaping in telecommunication system of mobile communication CDMA with application of intellectual antennas technology, using specified device and method, multiple fixed beams are shaped in sector, and multiple fixed beams are used to shape traffic channel with narrow beams and common channel with sector beams in one and the same intellectual antenna system, and problem of phases discrepancy is solved in appropriate channels due to differences in time and temperature oscillations without application of complicated correcting technology. Since fixed beams in some area correlate and interact with each other, or considerably weaken due to correlative summation of space vectors of every fixed beam in process of common channels transfer in CDMA system with multiple antennas, then appropriate ratio is established between power of pilot channel and traffic channel in coverage area, and signal-noise ratio is increased for signals received by mobile communication station. As a result of addition of optical transceivers system between system of the main frequency band and system of radio frequency transceivers (TRX), the main frequency band system services more sectors. Radio frequency unit is located in close proximity to antennas, and consumed power is reduced accordingly.

EFFECT: increased throughput capacity and efficiency of CDMA system with multiple antennas.

15 cl, 6 dwg

FIELD: information technologies.

SUBSTANCE: separation of transmitting antennas with feedback is applied to special channel of downstream communications line, and separation of transmitting antennas without feedback is applied to control channel of downstream communications line in accordance with high-efficiency method of transmission over upstream communications line. The objective of present invention is to determine how the station with separation during transmission which implements advanced upstream communications line (EUL) should apply separation of transmitting antennas to level 1 confirmation information transmission channels (E-HICH), relative transmission rate channels (E-RGCH) and absolute transmission rate channels (E-AGCH).

EFFECT: providing communications system stability and reliability.

9 cl, 15 dwg

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