MXPA97000382A - Variation of channel jumps in a radiocommunication system - Google Patents

Abstract

The invention relates to a method and to an arrangement for performing the base orthogonal channel hopping variation between the mobile stations (MS1-MS3) and a base station in a radio communication system. Connections (F1-F3) that have low attenuation are assigned to a number of channels that have high interference I (channel, t). Connections (F1-F3) that have higher attenuation are assigned to a number of channels that have lower interference I (channel, t). A channel allocation means (211) in the base station operates to produce channel skip sequences that are transferred to the skip sequence lists (204-206) in the mobile stations (MS1-MS3), through an SACCH control channel. The channel skip sequences are also transferred to the corresponding skip sequence lists (201-203) at the base station. The attenuation of the connections (F1-F3) and the interference in the I channels (channel, t) are measured continuously in the channel assignment means (211), where the best channels are used with respect to the interference. The channel allocation means creates the channel hopping sequences in accordance with the principle that the better a connection is with respect to attenuation, the more deficient the channels will be with respect to the interference that are allocated to the connection.

Description

"VARIATION BY CHANNEL JUMPS IN A RADIOCOMMUNICATION SYSTEM" TECHNICAL FIELD The present invention relates to the radiocommunication field and then particularly, but not exclusively, to a variation method for channel breaks having different channels of a radiocommunication system. The invention also relates to the radio communication system wherein the method is implemented.

DESCRIPTION OF THE BACKGROUND OF THE TECHNIQUE The term "variation by channel breaks" is used in this document as a collective designation for jumps between different transmission channels, for example, such as jumps only between frequencies, jumps only between time intervals and jumps between both frequencies as time intervals in a radiocommunication system. The person skilled in the art is aware of the fact that variation by frequency hopping can be used in a radiocommunication system to improve the operation of the radio system or to protect against unauthorized listening to radio communication, among others. things. The variation by frequency jumps is carried out in a predetermined order in these systems, without paying attention to the instantaneous quality of the connection. The variation by frequency jumps in radiocommunication systems is not adapted in this way. It can be established between the transmitter and receiver of a radio communication system and a radio connection through which radio communication can be made. The connection is bidirectional due to a link that forms the connection in one direction from a base station in the system to a mobile station, and an uplink that forms the connection in the opposite direction, from the mobile station to the mobile station. base. The transmission and reception of radio traffic for different connections is carried out on channels that can be defined by a certain frequency in the FDMA system or by a combination of a certain frequency and a certain time interval in a system using TDMA (Multiple Access) Division in Time). In a CDMA system, a channel can be defined by a code. Seen generally, the channels that remain available in a radiocommunication system are capable of being disturbed by other radio traffic to different degrees of disturbance, and also by radio signals on the same channels used for other connections, each channel having the system a certain level of interference. In this way, if each connection uses only one channel, the connections support different levels of interference. The levels of interference in certain connections can be so high as to avoid obtaining an acceptable connection quality. These disparities in the quality of the connection can be filled by variation by jumps between the different channels, where the connections use both channels of low and high interference levels. The use of high interference channels is dispersed between the different connections, and when the system is considered as a whole, more connections can be provided with an acceptable quality with the aid of interleaving coding and error correction. Each connection can be assigned a plurality of channels, where the system controls the connections as the communication takes place, causing the connection to jump between the channels in accordance with a given jump rule. This rule can be, for example, a predetermined pseudorandom series in which case the connections apparently jump randomly among all the available channels; see, for example, European Patent Application Number EP 93905701-4. However, the level of interference may become unnecessarily high when this type of variation by channel breaks is used., since channels are not always designated to connections in an optimal way when a pseudorandom series is used. A radiocommunication system will normally include a number of channels that can be used for connections between a particular base station and the mobile stations. In this case, it is important that the same channels are not used at the same time for two or more connections between the base station and the mobile stations. If two transmitters transmit different signals to their respective receivers simultaneously in one and the same channel, there may be a possibility that at least one receiver will be disturbed by interference of the transmission to the other receiver. If the aforementioned situation can not occur, that is, when only one connection of the base station can be transmitted in one channel at a time at any time, what is known as "orthogonality in the base station" or "is obtained". basic orthogonality ". When a connection in a radiocommunication system is excessively bad, where an acceptable connection quality is not obtained, this may be due to the fact that the relationship between the signal strength and the interference is too low, among other things. The intensity of the signal referred to in this respect is the intensity of the desired signal summarized. By "interference" is meant the sum of the signal intensities of all undesired signals received in the channel used. These undesirable signals come mainly from other connections that use the same channel in the adjacent cells, in the radio communication system. The unwanted signals received also originate from connections within their own cell or a local cell, using these connections an adjoining frequency or time slot. The intensity of the signal is contingent on the transmission power and also on the degree to which the desired signal has been attenuated as it passes from the transmitter to the receiver. The attenuation of the signal is determined, among other things, by distance, direction and topology between the transmitter and the receiver. Other terms used in parallel with attenuation are channel amplification or path gain (channel amplification is negative) and trajectory loss which are terms well known to a person skilled in the art. Several propositions related to different frequency of methods are well known in the art. The following examples of known techniques use the frequency hopping in different ways to achieve specific objects in different types of communication systems. The published German specification Number 3415032-A1 discloses a frequency hopping system wherein variation by frequency hopping is performed in a pseudo-random manner. The frequencies used are monitored and excluded from further use when they no longer have an acceptable level of interference. The North American Patent Specification Number 4,998,290 describes a radio system that uses variation by frequency hopping. The system includes a central check station that assigns frequencies for communication with several participating local radio stations. The testing station maintains an interference matrix that reflects the capacity requirement of the different radio stations and the interference status of all connections.

United Kingdom Patent Application Number GB 2,261,141 A discloses a method for using variation by frequency hopping in a radiocommunication system. The method involves monitoring the channels included in the jump sequence and replacing those channels that do not meet quality criteria with new channels. US Patent Specification Number 4,872,205 describes a frequency variation communication system. The system automatically detects when another radio system is within the range and then selects another group of frequency hopping sequences, with the intention of avoiding mutual interference between systems whose scales overlap each other. US Patent Specification No. 5,210,771 describes a communications system in which each channel is assigned a desired limit value for the received signal strength. A channel is assigned to a subscriber depending on the strength of the received signal at a receiving location and through the power control scale of the subscriber unit. In accordance with this patent specification, it is desirable to adjust the power of all users dynamically, such that the signals will be received with approximately the same power. US Patent Specification No. 4,670,906 describes the method for the dynamic selection of one of a plurality of radio transmitters to transmit message signals from a primary station to remote stations in a data communication system. The method involves measuring the signal strength of the carrier wave signal received by the base stations, with each transmission from an indicated remote station, calculating the loss of the path between the indicated distant station and each base station location, while the intensity of the signal measured for the receiver at this location is used, calculating the signal strength that can be received at the indicated remote station from each base station, and selecting at least one of the transmitters of the station basis for transmitting a message signal to the indicated remote station. The United Kingdom Patent Application Number GB 2,203,314 A describes a frequency hopping assignment system for radio stations of variation by frequency jumps. In accordance with an object of the invention described in this application, the hop data can be assigned to different networks in order to reduce the interference between the networks up to a level that does not prevent the radio stations from communicating with each other . The Specification of the North American Patent Number. 4,355,399 discloses a transmitter and receiver assembly that allows the operation of an associated user to be controlled by simultaneous selective transmission of one or more coded frequencies with each time slot of the transmitted sequence, wherein a higher degree of flexibility of the The system and / or the operation of the user with the worst reception conditions can be improved at the cost of those users who have better reception conditions, which results in the efficiency of the improved system as seen in total.

COMPENDIUM OF THE INVENTION The invention deals with the problem of how the channels will be assigned to different connections between a base station and mobile stations that are located within the area covered by the base station. The base station is included in a radio communication system that uses variation by channel breaks, and the channels are assigned so that the connections are not disturbed or altered one with respect to the other to an unnecessary degree, preferably to the smallest possible degree and so that good connection quality is obtained. The aforementioned problems include the problem of how the orthogonality within the base station can be secured. An object of the present invention is therefore to optimally use the channels available in a base station with respect to the connection quality of the connections between the base station and the mobile stations that are located within the protected area by the base station, while a method of variation by channel breaks is used for this purpose. Another object is to ensure the orthogonality in the base station or the base orthogonality, that is, to ensure that only one of the base station connections at the same time uses a channel that is available in the base station. The aforementioned problems are solved by means of a method that uses variation by channel breaks between a number of channels to which each connection is assigned. In a highly simplified form, the method of the invention involves determining the quality of the connection of the connections, eg, the attenuation of the signal and the channel quality of the channels, e.g., the interference. A number of the best channels are used with respect to channel quality where the connections where the signal attenuation is high are assigned channels that have the least interference from those channels used, and connections with small signal attenuation are assigned to channels that have the highest * interference of those channels used. More specifically, a method may comprise, measure or also determine a signal attenuation parameter such as path gain, for example, for connections. The connections are then placed in order according to the measured signal attenuation parameter. The method also includes measuring or determining in the predetermined channels, a channel quality parameter, such as interference, for example, for connections. The channel quality parameter can also be obtained by measuring the value of C / I or the bit error rate, BER, for example, and then calculating an interference value with the value of C / I or bit error rate as the entry data. The channels are then placed in order according to the measured channel quality parameter. Only the best channels are used with respect to the channel quality parameter. The channels are then assigned to the connections in accordance with the principle that a connection having high attenuation is assigned to a number of channels of high channel quality, and a connection with low attenuation is assigned to a number of channels of high quality. low channel (lowest). It will be noted that the designation of high and low channel quality refers to the quality of those channels that are actually used in the variation sequences by channel jumps. Channels that are not used in a variation sequence per channel hop will have poorer channel quality than the worst channel used in the channel hop variation sequence. The connections then jump between their assigned channels. The procedure can be repeated continuously or intermittently whereby the allocation of the channel to the "old" connections can be updated. Because the procedure is repeated, any of the newly established connections can also be channels allocated to jumps between them. The invention also relates to an arrangement for carrying out the method. The advantages provided by the invention lie in obtaining an adaptive channel assignment and a secure orthogonality in the base station. This results in the best use of the available channels due to the assignment to a connection that has low attenuation channels that have high levels of interference, ie, high interference in relation to the best channels used and due to the assignment to a connection that has high attenuation channels that have low interference levels, that is, low interference in relation to the best channels used. The advantages also provide improved connection quality in more connections, an increase in capacity and a lower level of total interference in the radio system. The invention will now be described in greater detail with reference to the preferred embodiments thereof and also with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure la is a schematic view of part of a radio communication system. Figure Ib is a schematic functional diagram illustrating the principle of variation by channel breaks. Figure 2 is a schematic functional diagram illustrating three mobile stations and a base station located in a cell in the radio system and also illustrating the channel hopping variation principle of the invention. Figure 3 is a schematic functional diagram illustrating a first exemplary embodiment of the invention. Figure 4 is a schematic functional diagram illustrating a second exemplary embodiment of the invention. Figure 5 is a schematic functional diagram illustrating a third exemplary embodiment of the invention. Figure 6 is a schematic functional diagram illustrating a fourth exemplary embodiment of the invention. Figure 7 is a flow sheet schematically illustrating the method of variation by channel breaks of the invention.

BEST WAYS TO CARRY OUT THE INVENTION Figure la is a schematic illustration of part of a radio communication system. The system illustrated in the Figure is a cellular public land mobile network PLMN that includes the base stations BS1-BS8. Each base station has a certain scale within which radio communication can be established with mobile radio stations or mobile stations MS1-MS6 placed within the coverage area defined by the scale of the base station. The cells C1-C8 represent the geographical areas covered by the base stations BS1-BS8. The base stations are connected to the remaining modes of the mobile radio network, such as the base station switching centers, the mobile switching centers and the mobile-access switching centers, in accordance with the known technology . These modes are not shown in the Figure nor are they described in detail in this context since they have no specific importance with respect to the present invention. Figure Ib is a schematic illustration of the principle of variation by channel breaks according to the present invention. The base stations in the radiocommunication system include jump sequence lists. These lists contain the information on which channels the base station uses in communication with the mobile stations placed within the area covered by the base station. Consequently, if a base station serves a plurality of connections to different mobile stations, a hop sequence list is found for each connection in the base station. In this way, the base station BS1 in the cell Cl includes a hop sequence list 101 for the connection to the mobile station MSI. The corresponding hop sequence lists for connections to mobile stations MS2 and MS3 are not shown in the Figure. The list 101 in the base station BS1 includes three channels chl-ch3 for transmission, the reference Tx and three channels ch4-ch6 for reception, reference Rx. In this way, the transmitter of the base station transmits in the chl channel in a first time interval? T = 0, a channel ch2 in a second time interval? T = 1 and in the channel ch3 in a third interval of time? time? t = 2, and it is said that these three channels form a sequence of channel jumps for transmission from the base station BS1 to the mobile station MSI. The transmission from the base station (and the mobile stations) may travel in time within the time intervals? T, the time intervals do not need to follow each other immediately in a TDMA system. The chl channel is again used in a fourth time interval repeating in this way the sequence of channel jumps. The sequence of channel jumps chl-ch3 is then repeated during a time interval where the radio connection is connected to the mobile station MSI, or until new channels are assigned to the jump sequence list 101, in accordance with the following explanation. The receiver in the base station BS1 receives in the channel ch4-ch6 in time interval? T = 0, 1 and 2, respectively, after which this sequence of channel jumps is repeated, similar to the procedure above described related to the transmitter. In this example, three channels are used in each channel skip sequence. However, the number of channels used in the channel hopping sequences constitutes a system parameter that can be selected in any appropriate manner, as will be described below. The mobile station MSI has a hop sequence list 102. The sequence of channel jumps in the hop sequence lists 101 and 102 are identical, even though the sequence of channel jumps that is used for transmission in the base station is of course used to receive in the mobile station, and the The sequence of channel jumps used for reception in the base station is used for transmission in the mobile station. Therefore, the channels chl-ch3 form the sequence of channel jumps when they receive, the channels ch4-ch6 form the sequence of channel jumps when transmitting for? T = 0, 1, 2, in the mobile station MSI.

The channels stored in the hop sequence list and used by the base stations and the mobile stations are selected in accordance with a method of the invention which will be described in greater detail below. However, certain fundamental principles can be mentioned at this point. Preferably, a sequence of channel breaks in the base station is generated, for example, the sequence of channel jumps for transmission from the base station. The sequence of channel jumps for reception at the base station can then be provided by so-called duplex separation which is the separation of the radio channel or frequency between the uplink and downlink as is generally known by the person skilled in the art. technique. The hop sequence list obtained in this manner in the base station is then transferred to the mobile station through a control channel where it is used as the hop sequence list for the mobile station, - in the manner above described. The transfer of the hop sequence list 101 to the hop sequence list 102 in the mobile station MSI is illustrated schematically by the broken line in the Figure. It is also possible to generate a sequence of channel jumps in the mobile station and then use the duplex separation to obtain the other sequence of channel jumps, acquiring with it a list of sequence of jumps for the base station. This list is then transferred to the base station in the control channel, as described above. Alternatively, the respective transmission channel hopping sequences and the reception channel hopping sequences may be generated for each connection either at the base station or at the mobile station, without using the duplex separation. This alternative can be used in systems that do not use a duplex separation, such as the DECT system, for example. This will be described below with reference to a modality illustrated in Figure 6. Figure 2 is a schematic functional diagram schematically illustrating the three mobile stations MS1-MS3 and the base station BS1 in cell 1 of the Figure of the Figure the. The base station includes a means such as circuits for the hopping lists 201-203 for each of the three connections between the subscribers al-a3, which can be static or mobile subscribers and the mobile stations MS1-MS3. Each of the mobile stations includes circuits for their list of respective sequence of jumps 204-206, these lists corresponding to the lists of sequence of jumps in the base station, as explained above. It is assumed in this example, that the hop sequence lists 201-206 include three transmission channels and three reception channels. The base station includes a transmitter / receiver part 205 that transmits / receives radio signals to / from the mobile stations on the assigned channels. The receiver 207 also receives interference signals from the channels used by other connections. Generally seen, this interference is contingent on the channel and time and, therefore, can be described as I (channel, t). Each of the mobile stations MS1-MS3 includes a respective transmitting / receiving part 208, 210 for the radio signals to / from the base station. An interference I (channel, t) is also received in the receivers of the mobile stations. The allocation of channels forming the channel skip sequences in the channel skip sequence lists is effected in a channel assignment means 211 in the base station BS1, as will be described in greater detail below. The channel skip sequences are then transferred from the channel assignment means 211 to the base station and the mobile station 201-203, 204-206 jump sequence lists., respectively, where a control channel such as the control channel SACCH (Slow Associated Control Channel) is used for transmission to the mobile stations, as mentioned above. The transfer of the channel hopping sequences to the hop sequence lists 204-206 is shown separately in the Figure by a broken line for reasons of clarity, even when done in a known manner with the help of transmitters / receivers. 207-210 under the control of the CPU control unit (Figure 3). The base station and the mobile stations are then known through the medium of the channel hopping sequences where the transmission and the channel receiver will be carried out in each time slot. Figure 3 is a schematic functional diagram illustrating the channel allocation means 211 in the base station BS1, in greater detail. The channel allocation means 211 includes a device 212 for generating a signal attenuation parameter that indicates the degree to which the radio signal has been attenuated or damped between the transmitter and the receiver, for a given connection. In principle, the signal attenuation parameter can be generated for a given connection between a base station and a mobile station, by transmitting a known signal intensity measurement signal from the base station to the mobile station. The mobile station registers the intensity of the received signal and discloses the value back to the base station, thereby allowing the parameter of signal attenuation to be calculated. In the mobile radio network, for example, the attenuation of the signal in connections to be established or that have already been established, is measured repeatedly. This measurement procedure is carried out with the help of the control channels in a known manner and, therefore, the operation function of the device 212 will not be described in detail in this context. The measurement of the signal attenuation parameter has been described here in the downlink, that is, with respect to a measurement signal transmitted from the base station. It will be understood that the measurement signal can be transmitted equally well from the mobile station in which case the signal attenuation parameter is measured in the uplink. However, the attenuation of the connection signal can be said to be the same both in the uplink and in the downlink with a good approximation and, therefore, is usually unimportant with respect to the application of the invention if the The parameter of the attenuation of the signal is determined in the uplink or in the downlink. The device 212 generates a list 213 of connections in which a signal attenuation parameter d ±, 62, ... is stored for the respective connections Fl, F2, ... The signal attenuation parameters stored in the list 213 of connections constitute the input data for the algorithm used to assign channels to the hop sequence lists in accordance with the following. A selection or classification device 214 compares the signal attenuation parameters with each other and stores the connections in accordance with the parameters in the list 215 of selected connections, wherein the connection having the lowest signal attenuation parameter is stored at the top of the list of connections. The connection that has the lowest signal attenuation parameter is called m0 in the selected list of connections 215, the connection that has the next lower signal attenuation parameter is called m ^ and so on, the sequence being, so both placed in sequence in accordance with the increased signal attenuation. When a connection has a low signal attenuation parameter, this will mean that the signal will have a small attenuation in the connection, the connection with it being of good quality with respect to the signal attenuation. The channel allocation means 211 also includes a device 216 for generating a channel quality parameter, which indicates the degree to which the channel has been disturbed by interference. In principle, the channel quality parameter of a given channel can be generated by repeatedly measuring the interference in the channel. Alternatively, other parameters can be measured or determined, for example, the channel bit error rate or the channel C / I value and an interference value is calculated from these values. In the case of a mobile radio network, for example, these channel interference measurements are repeatedly made in a known manner and the operation function of the device 216 will not be described in detail in this context. US Patent Specification No. 5,355,514 describes an example of the methods for measuring channel interference. The device 216 generates a channel list 217 in which the channel quality parameter II, 12, ... is stored for the respective chl, ch2, ... channels. The channel quality parameters stored in the channel list 217 constitute the input data for the algorithm used in channel assignment to the data sequence lists in accordance with the following. A selection or classification device 218 compares the quality parameters of channel one with the other and selects the channels in a list 219 of selected channel in accordance with the channel quality parameters. The channel that has the lowest channel quality parameter that is referenced as C0 in list 219"of the selected channel, the channel that has the lowest channel quality parameter next to which it is referenced as C ^ y so on, the channels being arranged in this way in a sequence according to the channel quality parameters that are raised.If a channel has a low channel quality parameter, the channel suffers only small interference and is good quality with respect to In the case of this mode, only the best channels with respect to the interference are stored in the list 219 of the selected channel, the number of stored channels being equal to the number of connections in the connection list. an alternative, the best channels are stored in the selected channel list in a number that exceeds the number of connections established at that moment in time. possibility of obtaining additional capacity in the form of sequences of finished channel breaks that are ready to be used immediately by a new connection, when the connection is established. The selected connection list 215 and the selected channel list 219 are connected to a device 220 to generate channel hop sequences. The device 220 allocates channels to the channel hopping sequences in accordance with an algorithm of the invention.

Expressed in simple terms, the algorithm works to assign to a connection that has low attenuation a number of low quality channels, which are expressed for example, as high interference and a connection that has high attenuation is assigned a number of channels that has high quality, which is expressed, for example, as low interference. This can be expressed in another simpler way by saying that "the better a connection is with respect to attenuation, the more deficient the channels will be with respect to interference, or with respect to some other measure of channel quality that will be assigned to the The channels can also be assigned to the connections in order to ensure orthogonality, that is, to ensure that no more than one base station connection uses the same channel at the same time The algorithm used to generate the hop sequences The channel can be expressed in the following mathematical terms: j = jm - jl - jh (1) where jm = k - l + i - 2 • module (i + module (t, k), k) jl = min ( jm + i - k + 1, 0) / 2 jh = maz (jm + i + k + 1 - 2 • n, 0) / 2 k = an integer representing the number of channels used by the transmitter and receiver in a connection, that is, the number of channels that form a sequence of channel jumps i = the connection m¿, t = the interval d e time (t = 0, 1, ..., k) n = the number of connections in the related time interval. j = channel Cj.

The module designation (x, y) is related to the value of the number and stages in a period including the values x. For example, periods 0, 1, 2, are obtained when x = 3. When y = 5, the value 1 is obtained which is the fifth stage in the period 0-1-2 (0-1-2-0- 1) . Therefore, m (3,5) = 1. If it is assumed that three channels are used with each sequence of channel breaks (k = 3) and that seven connections (m0-mg) are established between a base station and seven mobile stations, an algorithm of the aforementioned type can provide the following results.

CJ t 6 2 1 0 (2) 1 0 2 4 0 2 1 (? T = 0, 1, 2) twenty-one 0 2 1 0 _? My 0 1 2 3 4 5 6 The result is shown in a previous jump sequence matrix. (It will be noted that the matrix can be presented in different ways by re-indexing, thus allowing a more distinct matrix to be obtained above). It will be seen from the sequence of jumps matrix that the connection m0 (the best connection with respect to attenuation) has been assigned to a sequence of channel jumps consisting of the channel C4-C6 (the three worst channels with respect to interference) . Connection g (the worst connection with respect to attenuation) has been assigned to a sequence of channel breaks consisting of channels c0-C2 (the three best channels with respect to interference). An "average quality" connection, such as the m.3 connection, has been assigned to three channels of "average quality" c \, C3 and C5. Therefore, four connections are assigned with respect to the signal attenuation parameter to the successive channels which are successively better with respect to the channel quality parameter in a manner such as to obtain the base orthogonality. The numbers 0, 1 and 2 in the jump sequence matrix represent the time interval in which the channel is used through a specific connection. For example, connection 1114 uses channel C4 in time intervals? T = 1, 4, 7, 11, ... When the sequence matrix is examined row by row, or in other words, channel by channel, it is You will see that the base orthogonality is obtained due to a certain time interval that appears only once in each row. As mentioned above, a number k of predetermined channels are used in the channel skip sequences. The value of k is a system parameter and can be provided of any desired value. When the sequence of channel jumps includes several channels, there is less dependency on each channel in the sequence of jumps. When less number of channels are used in the sequence of channel jumps, each channel in the sequence, will generally be better than the channels in a sequence of jumps * that uses more channels. It should be noted that the value k can be determined for each base station and consequently the number of channels in two channel hopping sequences of two different stations can differ. The device 220 then generates a sequence of additional channel breaks for each condition m0-mg using the duplex separation as mentioned above. A sequence of channel jumps is then used by the transmitter of the base station and the other sequence of channel jumps is used by the receiver of the base station for respective connections. The two channel hop sequences for each connection are then stored in a respective hop sequence list in the base station, such as hop sequence lists 201-203 in Figure 3. The two channel hop sequences per connection are also sent to the mobile stations through a control channel SACCH are stored in the respective hop sequence lists in the mobile stations, such as lists 204-206 in Figure 2. There is an additional possibility in the use of a random or random number generator device 221 to increase the functionality of the device 220. The device 221 randomly generates a singular integer between 0 and k for each time interval referenced as 0, 1 and 2 in the matrix previously mentioned. The same channels as those previously used will be used in this way for each connection even when the order in which the channels appear in the sequence of channel jumps will be inverted randomly. For example, if 0 - >; 2, 1 - > 1, 2 - > 0, after the aleatorey generation in the devices 221, the hop sequence array will have the following appearance. This allows repetitive disturbances to be avoided between the channel hopping sequences of different base stations. 6 0 1 2 (3) 1 2 4 2 0 1 (? T = 0, 1, 2) 0 1 0 1 2 0 1 2 3 4 5 6 A control CPU unit of the channel assignment device 211 communicates with the previously described devices and controls the channel assignment procedure described. This communication is effected through the means of the control signals that are sent between the control CPU unit and the devices, where the control signals are sent on a line 222 between the control unit and the ports 212p, 213p, ..., 221p, as shown schematically in Figure 3. For reasons of simplicity and clarity, the CPU unit with line 222 and ports 212p, 213p, ..., 221p, is not shown in the following Figures . Figure 4 is a schematic functional diagram illustrating a second embodiment of the invention and channel assignment device 211. The selected channel list 219 is obtained in a manner different from that described with reference to the embodiment of Figure 3. In the case of the embodiment of Figure 4, the interference is measured in the downlink of each mobile station MS1- MS3. Therefore, each mobile station measures or likewise determines the interference of the channels and then sends the values to a list 401-403 of respective channel in the base station through a control channel, as illustrated schematically in the Figure with the broken line which is referred to as SACCH. This transmission of the measured interference values of the mobile stations to the channel lists in the base station is shown separately by the broken line in the Figure for reasons of clarity, even though the transmission is carried out in a known manner with the help of transmitters / receivers 207-210. The channel lists 401-403 correspond to the channel list 217 in Figure 3. In this way, the channel list 401, 402 and 403 includes a channel quality parameter II, 12, ... for the respective channels chl, ch2, ... this parameter being measured from the mobile station MSI, MS2 and MS3, respectively. A mean value generation and selection device 404 then calculates an average interference value for each channel and classifies or selects the channels in accordance with the calculated average interference values. The device 404 can produce an average value image with the help of any unambiguous reproduction class, which expands monotonously and non-linearly (e.g., logarithmic function) in order to avoid individual extreme measurement values in channel lists 401-403 to which an exaggerated importance in the final result is provided. A linear average value is then appropriately established after which the channels are sorted or selected in accordance with the average values formed in this way, that is, in accordance with the increased interference. Only the best channels with respect to the interference are then stored in the list 219 of the selected channel, the number of stored channels being equal to the number of connections similar to the modality of Figure 3. The remaining devices 212-215 and 220-221 they function in the same manner as in Figure 3 and, therefore, will not be described with reference to Fig. 4. Figure 5 is a schematic functional diagram illustrating a third embodiment of the invention and the channel assignment device 211. . Other than the other modalities described above which are illustrated in Figures 3 and 4, the selected channel list 219 is obtained with the aid of the interference measurement values of both the uplink and the forward link. In the case of the embodiment of Figure 5, the interference is measured in the downlink of each mobile station MS1-MS3 in the same manner as that described with reference to Figure 4. The interference values measured in the uplink and stored in channel list 217. This is achieved using the device 216 to generate the channel quality parameter and the channel list 217 in the same manner as that described with reference to Figure 3. However, in the case of the embodiment of Figure 5, the channel list 217 is connected to the medium value and selection device 404 which operates in accordance with the principle described with reference to the embodiment of Figure 4. This allows the interference values measured in the uplink to be used to calculate the average interference values. In Figure 5, devices 212-215 of Figure 4 have been shown as a single device 405 for reasons of space. The operation function of the device 405, therefore, corresponds to the operating functions of the devices 212-215 shown in Figure 4. Figure 6 is a schematic functional diagram illustrating a fourth embodiment of the invention and the device 211 of channel allocation. Unlike the previously described modes, the duplex separation is not used to create the channel hopping sequences. Therefore, the device 220a generates only a channel hop frequency, whose hop sequence can be used when transmitting from the base station, for example. The channel hopping sequence generator 220b operates in accordance with the same principles as the device 220a and generates a sequence of channel jumps for each connection in accordance with the hop sequence algorithm, these channel hopping sequences being used for reception at the base station when the channel hopping sequences generated in the device 220a are used for transmission in the base station. The device 220a receives the channel input data from the device 219a. This channel input data has been obtained by measuring the interference in the downlink as described with reference to Figure 4. The device 220b receives the channel input data of the device 219b. This channel input data has been obtained by measuring the interference in the uplink as described with reference to Figure 3. Because the interference values measured in the uplink and the downlink are not mixed in the device 404, as described with reference to Figure 5, completely independent channel hopping frequencies can be generated in devices 220a-220b, where a channel hopping sequence is used for transmission and another sequence of channel hopping is used for reception at the base station. The channel hop sequences are stored in the base station in lists 201-203, sequence of jumps and are transmitted in the channel of the SACCH control to lists 204-206 of sequence of jumps in the mobile stations, of the same way that the one described in the foregoing. Figure 7 is a flow sheet illustrating a channel hop method of the invention. The signal attenuation parameter d is generated in step 701 for the established connections F1-F3. The signal attenuation parameter can be generated by measuring the attenuation in the uplink and / or the downlink of each connection.

The channel quality parameter is then generated in step 702 for each chl-chn channel. The term "each channel" may be related to all channels in a base station or in the telecommunications system as a set or to a predetermined subgame of these channels. The channel quality parameter can be generated by measuring the interference in the uplink and / or the downlink of each channel. Other magnitudes can be measured, such as the C / I value or the bit error rate and an interference value for each channel can be calculated as the input data based on these quantities. The signal attenuation parameters and channel quality parameters are stored in the respective connection lists and channel lists 213, 217 in step 703. In step 704, the connections are stored in accordance with the attenuation parameter measured signal (attenuation) and the connections are then stored in the selected connection list 215. When the measurement values are used for the uplink or both for the uplink and the downlink, an average attenuation value is calculated for Each connection and connections are then selected according to the calculated average value.

In step 705, the channels are selected in accordance with the measured channel quality parameter (of the interference) and the best channels with respect to the interference are then stored in the selected channel list 219. If the measurement values of the uplink or both the ascending link and the downlink are used, an average interference value is calculated for each channel and the channels are then selected in accordance with the calculated average value. The number of channels stored in the selected channel list can be at least equal to the number of connections established at each moment in time. When the number of channels is equal to the number of connections, each channel will be used by one of the connections in each time interval. A free capacity (free channel hopping frequencies) can be obtained by storing more channels in the selected channel list than the number of established connections, this free capacity being immediately available for use when a new connection is to be established. The preferred hop sequence algorithm described above is applied in step 706. This provides a sequence of channel jumps for each connection wherein the sequence of channel jumps can be used for transmission either from the base station or from the mobile station. A sequence of channel jumps corresponding to that used for reception can be obtained using the duplex separation as mentioned above. A further possibility is one to produce channel hopping sequences for both transmission and reception for each connection, with the help of the hop sequence algorithm, ie without using the duplex separation. It will be understood that a sequence of channel jumps that is used for transmission in the base station can be used for reception in the mobile station and that the sequence of channel jumps that is used for transmission in the mobile station will be used for reception at the base station. In step 707, a check is made to ensure whether the allocation of channel hop sequences to the hop sequence lists 201-203, 204-206 will be updated or not. If the constestation is positive (yes) in accordance with alternative J, the channel hopping sequences are stored in step 708 and the procedure is then repeated from step 701. If the answer is negative (no) in accordance with a alternative N, the procedure is repeated from step 701 without updating the assignment. If the channel hop sequences will be updated or not, it is therefore determined, by a monitoring procedure carried out in step 707, for example, with the help of the control CPU unit. The channel allocation device 211 is capable of continuously creating "new" channel hop sequences where a new channel hop sequence can replace an "old" channel hop sequence, for example, when the quality disparity The call for the two sequences of channel jumps exceeds a predetermined level value, or when the level of interference exceeds a predetermined value. The update does not need to be a complete update, that is, the channel hop sequences need to be updated only with respect to those connections where the disparities in call quality exceed the limit value. Among other things, the update may be necessary when new connections are established or when the reception conditions due to the movement of the mobile stations are changed. In step 708, the generated channel hopping sequences are stored in lists 201-203, 204-206, of hopping sequence in the base station and in the mobile stations, when it is secured in step 707 that it will be carried out the update. The base station has a hop sequence list for each connection and each of the hop sequence lists includes channel hopping sequences for transmission and reception, respectively. The sequences of transmission and reception channel jumps to be used by the mobile stations are sent to these stations through an SACCH control channel and then stored in the respective hop sequence lists in the mobile stations. The procedure is repeated after step 708, where the hop is made to step 701. As an alternative, step 704 and 705 may be omitted where the information stored in the connection lists and channel lists 213, 217 they constitute the input data for the jump sequence algorithm used in step 706. It will be noted that in this case, the jump sequence algorithm does not work in the manner described above. Because no selected connection lists and channel lists have been produced, the hop sequence algorithm itself must find those channels that can be used and assign these channels to the correct connection. In this way, the actual jump sequence algorithm can be implemented in several ways, even though all the algorithms operate in accordance with the principle that the better the connection with respect to a more deficient signal damping parameter, the more with respect to a channel quality parameter that is assigned to the connection. As an alternative, the hop sequence lists in the stationary base stations may include only one sequence of channel jumps. In this case, means are provided to generate a sequence of additional channel breaks for each connection, e.g., using the duplex separation. The aforementioned means then allocates one of the sequences of channel jumps to the transmitter and the other frequency of jumps to the receiver. In the preferred embodiments described above, the radiocommunication system has been described as including base stations within whose respective coverage areas available channels are used in orthogonal base channel hopping sequences in communication or with those mobile stations that are located within of the area covered by a specific base station. The base station can be considered, generally, as a first radio station and the mobile stations as a number of second radio stations. The available channels within a radio coverage area can comprise either a number of channels that are specifically allocated to the base station, a subset of the total number of channels or all the channels in the radiocommunication system, signal attenuation parameters for these channels being generated. It is also possible to implement parts of the modalities described in the mobile switching center, MSC, or in a base station switching center, BSC, which in this case will include means for achieving the functionality of the means and devices described above. While the Figures illustrate mobile stations carried by the vehicle, it will be understood that the invention can also be applied to systems using hand-held portable mobile stations. It will also be understood that the invention is not restricted to the above described exemplary embodiments of the same that modifications may be made within the scope of the following claims.

Claims (24)

R E I V I N D I C A C I O N E S;

1. A method of variation by channel breaks in a radiocommunication system (PLMN) where the variation by channel breaks is made between the channels (chl-ch6) for the connections (F1-F3) between a base station (BS1) and at least one mobile station (MS1-MS3) in the radiocommunication system, and where the connections are subject to attenuation and interference of signal, the method comprising the steps of: generating a signal attenuation parameter (d) for the respective connections (F1-F3); generate a channel quality parameter (I, C / I, BER) for the respective channels (chl-ch6); - generating at least one sequence of channel jumps for the respective connections, wherein a sequence of channel jumps includes a number (k) of channels between which the connection jumps, and wherein the sequence of channel jumps is generated in accordance with the signal attenuation parameter (d) of the connections and the channel quality parameter (I, C / I, BER) of the channels; aning the channel skip sequences to a respective skip sequence list (201-203, 204-206) at the base station and at the mobile stations; and variation by channel breaks between the channels (chl-ch6) in the channel hop sequences that have been aned to the hop sequence lists when communicating by radio at the connections between the base station and the mobile stations.

2. A base orthogonal channel hopping variation method in a radiocommunication system (PLMN), where the variation of channel jumps is made between the channels (chl-ch6) for the connection (F1-F3) between a base station (BS1) and at least one mobile station (MS1-MS3) in the radiocommunication system, wherein the connections are subjected to attenuation and signal interference, and wherein the method comprises the steps of generating a parameter of signal attenuation (d) for the respective connections (F1-F3); generate a channel quality parameter (I, C / I, BÉR) for the respective channels (chl-ch6); generating at least one sequence of channel jumps for the respective connections, the channel hopping sequences being base orthogonal so that at most one of the connections (F1-F3) will use a designated channel in the base station ( BSl) at each time point (t = 0, 1, ..., k) where a sequence of channel breaks includes a number (k) of channels between which the connection jumps, where at least one is generated a sequence of channel jumps in accordance with the signal attenuation parameter (d) of the connections and the channel quality parameter (I, C / I, BER) of all channels; an the channel hop sequences to a respective hop sequence list (201-203, 204-206) at the base station. and in mobile stations; and the variation by channel breaks between the channels (chl-ch6) in the base orthogonal channel hopping sequences that have been aned to the jump sequence lists when communicating with radio in the connections between the base station and the mobile stations.

3. A method according to any of claims 1 or 2, wherein the generation of the hop sequence comprises: selecting the best connection with respect to the signal attenuation parameter (d); an the worst channels with respect to the channel quality parameter (I, C / I, BER) to the best connection in a number corresponding to the number (k) of channels, these worst channels form using sequence of channel jumps for the better connection; select succeely more deficient connections with respect to the signal attenuation parameter; an succeely better channels with respect to the channel quality parameter to the succeely weaker connections, in a number that coincides with the number (k) of channels, where the succeely better channels form a sequence of channel breaks for the connections succeely more deficient; select the most difficult connection with respect to the signal attenuation parameter; and - assigning the best channels with respect to the channel quality parameter to the most deficient connection in a number that matches the number (k) of channels, where these better channels form a sequence of channel jumps for the most deficient connection .

4. A method according to any of claims 1 to 3, comprising the steps of selecting or classifying the connections with respect to the signal attenuation parameter (d); and storing the selected connections in a selected connection list (215), wherein the connections are stored while selected in accordance with the signal attenuation parameter.

5. A method according to any of claims 1 to 4, comprising the steps of selecting the best channels (chl-ch6) with respect to the channel quality parameter (d) in a number corresponding to the number of connections, and generate channel hopping sequences for established connections (F1-F3); and storing the selected channels in the selected channel list (219), the channels being stored in a selected manner according to the channel quality parameter.

6. A method according to any of claims 1 to 4, comprising the steps of selecting the best channels (chl-ch6) with respect to the channel quality parameter (d) in a number that exceeds the number of connections, wherein the channel hopping sequences for connections that have not yet been established are generated before the connection is established; and storing the selected channels in a selected channel list (219), wherein the channels are stored classified or selected according to the channel quality parameter.

A method according to any of claims 5 and 6, wherein the respective connections (F1-F3) are selected according to their positions in the selected connection list (215) and where the canals are assigned to connections selected in accordance with the connections and in accordance with the positions of the channels in the selected channel list (219).

8. A method according to claim 7, wherein the channel assignment is orthogonal base.

9. A method according to claim 8, wherein the generation of the channel hopping sequences includes generating an additional channel hop sequence for each channel hop sequence that has already been generated, using a duplex separation, in where the pairs of channel hopping sequences are generated for the connections (F1-F3) and wherein the channels in each pair of channel hopping sequences are mutually separated by duplex separation.

A method according to claim 8, wherein the generation of the channel hopping sequences comprises the steps of generating two channel hopping sequences for the respective connections (F1-F3), wherein the hopping sequences of channel are generated in accordance with the signal attenuation parameter (d) of the connections and in accordance with the channel quality parameter (I, C / I, BER) of the channels for both channel hopping sequences.

11. A method according to claim 10, wherein the signal attenuation parameters (d) for the connections (F1-F3) are generated by measuring the attenuation of the signal in the uplink.

12. A method according to claim 10, wherein the generation of the signal attenuation parameters (d) for the connections (F1-F3) includes the measurement of the attenuation of the signal in the downlink.

13. A method according to claim 10, wherein the generation of the channel quality parameters (I, C / I, BER) includes measuring one of the following group of values, the interference value, the value of C / I and the bit error rate (BER) value for the channels in the uplink.

14. A method according to claim 10, wherein the generation of the channel quality parameters (I, C / I, BER) 'includes measuring one of the following group of values of the interference value, the C / I value and the bit error rate value (BER) for the channels in the downlink and form of these values a mean value related to one and the same channel.

15. A method according to claim 10, wherein the generation of the channel quality parameters (I, C / I, BER) includes measuring one of the following group of values, the interference value, the value of C / I and the bit error rate value (BER) for the channels in both the uplink and the downlink, and form from these values an average value that relates to one and the same channel.

16. A method according to claim 10, wherein the generation of the channel quality parameters (I, C / I, BER) includes measuring the values for those channels that have been assigned to the base station.

17. A method according to claim 1, wherein the generation of the channel quality parameters (I, C / I, BER) includes measuring the values for a subgame of all the channels included in the radiocommunication system.

18. A method according to claim 1, wherein the generation of the channel quality parameters (I, C / I, BER) includes measuring the values for all the channels included in the radiocommunication system.

19. A method according to claim 18, wherein the channel hop sequence assignment includes transmitting one of the channel hop sequences in the pair to a respective hop sequence list (201-203, 204 -206) in the base station (BS1) and in the mobile station (MS1-MS3), respectively.

20. A method according to claim 19, which comprises transferring the channel hopping sequences to the channel hopping lists (204-206) of the mobile stations (MS1-MS3) through a control channel (SACCH). ).

21. A provision related to radiocommunication systems and including a base station (BS1) and at least one mobile station (MS1-MS3), wherein the variation by channel breaks is carried out between the channels (chl- ch6) for the connections (F1-F3) between the base station and the mobile stations and where the connections are subject to signal attenuation and interference characterized in that the arrangement further includes means (212) for generating an attenuation parameter of signal (d) for the respective connections (F1-F3); means (216) for generating a channel quality parameter (I, C / I, BER) for the respective channels (chl-ch6); means (220) for generating at least one sequence of channel jumps for the respective connections, wherein a sequence of channel jumps includes a number (k) of channels between which the connection jumps, and wherein the sequence of Channel jumps are generated in accordance with the signal attenuation parameter (d) of the connections and the channel quality parameter (I, C / I, BER) of the channels; and a means (CPU) for assigning the channel hop sequences to a respective jump sequence list (201-203, 204-206) of the base station and the mobile stations and to control the variation by channel hopping between the channels (chl-ch6) in the channel hop sequences that have been assigned to the hop sequence lists when communicating via radio connections (F1-F3) between the base station (BS1) and the mobile stations ( MS1-MS3).

22. An arrangement related to radiocommunication systems wherein the arrangement includes a base station (BS1) and at least one mobile station (MS1-MS3), wherein the variation by orthogonal base channel breaks is made between the channels ( chl-ch6) for the connections (F1-F3) between the base station and the mobile stations, and where the connections are subject to signal attenuation and interference, characterized in that the arrangement also includes - means (212) for generating a signal attenuation parameter (d) for the respective connections (F1-F3); means (216) for generating a channel quality parameter (I, C / I, BER) for the respective channels (chl-ch6); means (220) for generating at least one sequence of channel jumps for the respective connections, wherein the channel hopping sequences are orthogonal in base so that the majority of one of the connections (F1-F3) will use a indicated channel (chl-ch6) within the base station (BS1) at each time point (t = 0, 1, ..., k) and where a sequence of channel breaks includes a number (k) of channels between which the connection jumps, and wherein at least one sequence of channel jumps is generated in accordance with the signal attenuation parameter (d) of the connections and the channel quality parameter (I, C / I) , BER) of the channels; and a means (CPU) for assigning the sequence of channel jumps to a respective jump sequence list (201-203, 204-206) of the base station and the mobile stations, and to control the variation by channel jumps. between the channels (chl-ch6) in the base orthogonal channel hop sequences have been assigned to the hop sequence lists when communicating by radio at the connections (F1-F3) between the base station (BS1) and the mobile stations (MS1-MS3).

23. An arrangement according to any of claims 21 and 22 comprising means (214) for selecting the connections with respect to their signal attenuation parameter (d); and means (215) for selecting the selected connections, wherein the connections are stored selected or classified according to the signal attenuation parameter.

24. An arrangement according to any of claims 21 to 23, comprising means (218) for classifying the best channels with respect to their channel quality parameter; and a means (219) for selecting the classified channels where the channels are stored classified or selected in accordance with the channel quality parameter. SUMMARY OF THE INVENTION The invention relates to a method and to an arrangement for performing the base orthogonal channel hopping variation between the mobile stations (MS1-MS3) and a base station in a radio communication system. Connections (F1-F3) that have low attenuation are assigned to a number of channels that have high interference I (channel, t). The connections (F1-F3) that have the highest attenuation are assigned to a number of channels that have less interference I (channel, t). A channel allocation means (211) in the base station operates to produce channel skip sequences that are transferred to the skip sequence lists (204-206) in the mobile stations (MS1-MS3), through an SACCH control channel. The channel skip sequences are also transferred to the corresponding skip sequence lists (201-203) at the base station. The attenuation of the connections (F1-F3) and the interference in the I channels (channel, t) are measured continuously in the middle (211) channel allocation, where the best channels are used with respect to interference. The channel allocation means creates the channel hopping sequences in accordance with the principle that the better a connection is with respect to attenuation, the more deficient the channels will be with respect to the interference that are assigned to the connection.