Abstract:
The invention makes configuring satellite decoders easier. An automatic detection method can configure the decoder without having to determine the installation beforehand. The automatic detection method tests different configuration possibilities in order to determine the used antenna system. A series of input selection commands are sent for a remote antenna switch corresponding to a given range of switch control possibilities, the said range being independent from the used antenna system.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a method for automatically detecting an antenna system for satellite receivers.  
       DESCRIPTION OF THE PRIOR ART  
       [0002]     Satellite television requires a special satellite receiver to receive the programmes broadcast by satellites, such receivers are generally called satellite decoders or STB (Set Top Box). Several satellites can be viewed from a given geographic location. Decoders are commercialised to be able to receive the signals coming from different satellites. It is therefore possible to couple a decoder to one or more fixed or rotating antennas to be able to receive the programmes from different satellites.  
         [0003]      FIG. 1  shows an example of a satellite installation that comprises a decoder  1  coupled to a television  2  to receive signals from two fixed antennas  3  and  4  and a motorised rotating antenna  5 . The antennas  3  to  5  are connected to the decoder by a switch  6 . To control this installation, the decoder must be configured to be informed that the installation has several antennas coupled to a switch and a minimum amount of knowledge of the antenna system used is required. Moreover, if one counts all the possibilities offered, the configuration menu becomes relatively complex and may require the presence of a specialist engineer. Moreover, if the antenna system is common to several decoders placed in a single building, an installer does not necessarily know the installation.  
         [0004]     The invention proposes to make configuring the satellite decoders easier. An automatic detection method can configure the decoder without having to determine the installation beforehand. The automatic detection method tests different configuration possibilities in order to determine the configuration.  
       SUMMARY OF THE INVENTION  
       [0005]     The invention is a method for automatically detecting an antenna system for satellite receivers that sends a series of input selection commands for a remote antenna switch corresponding to a given range of switch control possibilities, the said range being independent from the antenna system used.  
         [0006]     Preferentially, the series of selection commands is sent with at least one series of frequency positioning controls carrying out a satellite band scan, the said positioning controls being inserted between the said selection commands. The series of selection commands is sent with frequency and polarisation positioning controls corresponding to memorized satellite service channels, the said positioning controls being inserted between the said selection commands. At least one azimuth motion control is sent independently from the presence or absence of an azimuth elevation motorised antenna. At least one azimuth motion control sequence is sent independently from the presence or absence of an azimuth elevation motorised antenna. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The invention will be better understood, and other specific features and advantages will emerge from reading the following description, the description making reference to the annexed drawings wherein:  
         [0008]      FIG. 1  shows an example of a satellite receiver installation,  
         [0009]     FIGS.  2  to  4  show the different flow diagrams used by a preferred method realized according to the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0010]     The method according to the invention can detect the entire installation constituting an antenna system to which a decoder is connected. The decoder itself will carry out a complete analysis of the system and automatically configure itself.  FIG. 2  shows an overall auto-configuration flow diagram that comprises a first switch detection phase  100 , a second motorised antenna detection phase  200  and a third satellite and channel identification phase  300 . This flow diagram corresponds to an auto-configuration program that is run by a processor of the decoder. The user only has to run the auto-configuration of the decoder and wait, which is relatively simple.  
         [0011]     Firstly, it should be remembered that the DiSEqC standard is a standard that enables commands to be transmitted to an antenna system. Among the DiSEqC commands, it must be recalled that they comprise: 
        commands for the antenna transposition circuit commonly called LNB (Low Noise Block) that can select the polarisation of the waves received and the part of the satellite band transposed into intermediate band,     switch commands that enable a switch to be addressed, or cascaded switches enabling up to four inputs to be addressed, commonly called A, B, C and D,     motion commands for mobile azimuth elevation motorised antennas.        
 
         [0015]     The DiSEqC standard is the standard most used for satellite reception antenna but other commands can also be used. In the present description, abstraction is made of there being several types of command other than the DiSEqC standard in order not to make the description unnecessarily cumbersome. Since, as those skilled in the art will note, the method implemented considers in its first approach that all the possibilities offered are used.  
         [0016]     For DiSEqC, it is possible to have up to four switched antennas. In the detection method that will be detailed hereafter, four variables representative of any switch input(s) will be used: Input A, Input B, Input C and Input D, each of these variables can have the value “1” representative of the presence of this input on a switch, or the value “0” representative of the absence of the input. Considering that for each entry, it is possible to have a fixed or motorised antenna or no antenna, each possible switch input is assigned a signal variable: Signal A, Signal B, Signal C and Signal D, each of these variables being able to take the value “0” representative of the absence of the antenna, the value “1” representative of a fixed antenna or even the value “2” representative of a motorised antenna.  
         [0017]     Before running the auto-configuration, it is considered that there are switches with four inputs, the Input A, Input B, Input C and Input D variables are all set to the state “1”.  
         [0018]     Phase  100  is first carried out, in which only switches with fixed antennas are considered. During the first step  101 , the command that selects input A is sent, if there is a switch, this switch will be set to the corresponding input, otherwise this command will have no effect. Next, a second step  102  is carried out that consists of performing a rapid scan of the satellite band. The rapid scan is for example realised by using a relatively large pitch or only on frequencies and polarisations corresponding to the service channels of each known satellite, this step terminates after scanning the entire band (or all the tested frequencies) or as soon as a channel is found.  
         [0019]     If no channel has been found at the end of the second step  102 , then the Signal “A” variable is marked as equal to “0” during a third step  103 . Then, during a fourth step  104 , a selection command of an input B is sent. Then a fifth scanning step  105  identical to the second step  102  is carried out.  
         [0020]     If, at the end of the fifth step  105 , no channel has been found, then the Signal B variable is marked as equal to “0” during a sixth step  106 . Then, during a seventh step  107 , a selection command of an input C is sent. Then an eighth scanning step  108  identical to the second step  102  is carried out.  
         [0021]     If no channel has been found at the end of the eighth step  108 , then the Signal C variable is marked as equal to “0” during a ninth step  109 . Then, during a tenth step  110 , a selection command of an input D is sent. Then an eleventh scanning step  111  identical to the second step  102  is carried out.  
         [0022]     If no channel has been found at the end of step  111 , the Signal D variable is marked as equal to “0” during a twelfth step  112 .  
         [0023]     If a channel was found at the end of step  102 , the Signal A variable is marked as equal to “1” during a thirteenth step  113 . Still during the third step  113 , information relating to the channel received is memorized, among other things the identification of the channel but also the receiver power, error rate and possibly equalisation parameters. Then, during a fourteenth step  114 , the selection command of an input B is sent, without changing the channel selected. If, just after selecting input B, a signal is received that corresponds to the same signal as signal A whose parameters are memorized, then the Input B variable is marked as equal to “0” during a fifteenth step  115 . Indeed, if for the same channel polarisation and frequency, the channel received is the same with the same power and equalisation parameters, then this can only be the same antenna so the input the selection command of the input B is without effect and there is therefore no input B. Then, during a sixteenth step  116 , the input C selection command is sent without changing the channel selected. If, just after selecting input C, a signal is received that corresponds to the same signal as signal A whose parameters are still memorized, then the input C variable is marked as equal to “0” during a seventeenth step  117 . Then, during an eighteenth step  118 , the selection command of the input D is sent, without changing the channel selected. If, just after selecting input D, a signal is received that corresponds to the same signal as signal A whose parameters are still memorized, then the Input D variable is marked as equal to “0” during a nineteenth step  119 .  
         [0024]     However, if no signal, or a different signal from the one memorized, is received after the fourteenth step  114  then the fifth step  105  is carried out.  
         [0025]     If, a channel is found at the end of the fifth step  105 , then the Signal B variable is marked as being equal to “1” during a twentieth step  120 . During the twentieth step  120 , the information relating to the channel received is memorized, in an identical manner to that of the thirteenth step  113 . Then, during a twenty-first step  121 , the selection command of an input C is sent without changing the channel selected. If, just after selecting input C, a signal is received that corresponds to the same signal as signal B whose parameters are still memorized, then the input C variable is marked as equal to “0” during the seventeenth step  117 . Then, during an eighteenth step  118 , the input D selection command is sent without changing the channel selected. If, just after selecting input D, a signal is received that corresponds to the same signal as signal B whose parameters are still memorized, then the Input D variable is marked as equal to “0” during a nineteenth step  119 .  
         [0026]     However, if no signal, or a different signal from the one memorized, is received after the twenty-first step  121 , then the eighth step  108  is carried out.  
         [0027]     If, a channel is found at the end of the eighth step  108 , then the Signal C variable is marked as being equal to “1” during a twenty-second step  122 . During the twenty-second step  122 , the information relating to the channel received is memorized, in an identical manner to that of the thirteenth step  113 . Then, during a twenty-third step  123 , the selection command of an input D is sent without changing the channel selected. If, just after selecting input D, a signal is received that corresponds to the same signal as the signal C whose parameters are still memorized, then the Input D variable is marked as equal to “0” during a nineteenth step  119 .  
         [0028]     However, if no signal, or a different signal from the one memorized, is received after the twenty-third step  123 , then the eleventh step  111  is carried out.  
         [0029]     If a channel has been found at the end of step  111 , the Signal D variable is marked as equal to “1” during a twenty-fourth step  124 .  
         [0030]     Normally, if a switch is present, it has two or four switched inputs or may comprise two or three switches with two cascaded inputs. The manner in which the selection command is composed means that, normally, input A is always an input used as soon as a switch is also used, it is possible to consider the first phase  100  as being terminated at the end of the twelfth step  112 , the nineteenth step  119  or the twenty-fourth step  124 . If the signal A variable equals “1”, this means that there is indeed an input A. If the Input B, Input C and Input D variables are all equal to “0”, this means that there is no switch.  
         [0031]     The switches are normally identified at the end of the first phase  100 . However, it is possible that the final result is not reliable, as one or more motorised antennas can be present without however pointing to a satellite. If, for example, all the Signal A to D variables are equal to “0”, it is not possible to determine whether this is because the inputs are not connected to antennas or whether one or more motorised antennas are present, hence the necessity of repeating the first phase  100  in this specific case after the detection of a motorized antenna.  
         [0032]     The second phase  200  comprises a first type of processing in the case that all the Signal A to D variables are equal to “0” and a second type of processing in the other case.  
         [0033]     If all of the Signal A to D variables are equal to “0”, then input A is selected during a first step  201 . Azimuth scanning is then carried out during a second step  202 . Azimuth scanning consists of sending an instruction to set the antenna to the end of its travel, for example to the east, of sending instructions to the LNB to set the polarisation and the frequency band on a band in which there is at least one service channel for at least one satellite, of setting the tuner and demodulator of the receiver on a service channel then of sending instructions to move it toward the opposite end, for example to the west, until the other end is reached or a signal is detected that is not necessarily the one that corresponds to the required channel.  
         [0034]     If a signal is detected at the end of the second step  202 , then a third step  203  is carried out that consists of rerunning the first phase  100 , thus ending the second phase  200 .  
         [0035]     If no signal is detected at the end of the second step  202 , then a fourth step  204  is carried out. The fourth step  204  consists in selecting the input B. Then, a fifth step  205  realises an azimuth scanning, in the same manner as in the second step  202 .  
         [0036]     If a signal is detected at the end of the fifth step  205 , then a sixth step  206  is carried out that consists in rerunning the first phase  100 , thus ending the second phase  200 .  
         [0037]     If no signal is detected at the end of the fifth step  205 , then a seventh step  207  is carried out. The seventh step  207  consists in selecting the input C. Then, an eighth step  208  realises an azimuth scanning, in the same manner as in the second step  202 .  
         [0038]     If a signal is detected at the end of the eighth step  208 , then a ninth step  209  is carried out that consists in rerunning the first phase  100 , thus ending the second phase  200 .  
         [0039]     If no signal is detected at the end of the eighth step  208 , then a tenth step  210  is carried out. The tenth step  210  consists in selecting the input B. Then, an eleventh step  211  realises an azimuth scanning, in the same manner as in the second step  202 .  
         [0040]     If a signal is detected at the end of the eleventh step  211 , then a twelfth step  211  is carried out that consists in rerunning the first phase  100 , thus ending the second phase  200 .  
         [0041]     If no signal is detected at the end of the eleventh step  211 , then a thirteenth step  213  is carried out. The thirteenth step  213  consists of displaying to the user that no antenna has been detected and that the correct connection of the antenna input of the decoder to a satellite antenna system must be checked. This thirteenth step ends the second phase  200  and also the auto-configuration program without carrying out the third phase  300 .  
         [0042]     If at least one of the Signal A to D variables is not equal to “0”, then systematic detection is performed for each input whose Input A to D variable is equal to “1”.  
         [0043]     If the Input A variable equals “1”, then a fourteenth step is carried out that selects the input A. Then, if the Signal A variable equals “0” then a fifteenth step  215  is carried out, otherwise a sixteenth step  216  is carried out. The fifteenth step  215  is an azimuth scanning step of the same type as the second step  202 . The sixteenth step  216  consists of memorizing the channel received then) sending a motion command of an angle greater than the opening of a satellite antenna, for example, 3° to the east or west.  
         [0044]     At the end of the fifteenth step  215 , a check that a signal is received is made. If a signal is received, then the Signal A variable is set to the value “2” during a seventeenth step  217 . If no signal is received, then the Signal A variable is set to the value “0” during an eighteenth step  218 .  
         [0045]     At the end of the sixteenth step  216 , a check is made on whether a signal received corresponds to the channel previously received; if this is the case, the antenna has not moved and therefore it is fixed. If a signal is received, then the Signal A variable is set to the value “1” during a nineteenth step  219 . If no signal is received, then the Signal A variable is set to the value “2” during the seventeenth step  217 .  
         [0046]     If the Input A variable does not equal “1” or the seventeenth, eighteenth or nineteenth step  217  or  218  or  219  is finished, then a check is made on whether the Input B variable equals “1”. If the input B variable equals “1” then a twentieth step  220  is carried out that selects the input B. Then, if the Signal B variable equals “0” a twenty-first step  221  is carried out, otherwise a twenty-second step  222  is carried out. The twenty-first step  221  is an azimuth scanning step of the same type as the second step  202 . The twenty-second step  222  consists of memorising the channel received and sending a motion command identical to the sixteenth step  216 .  
         [0047]     At the end of the twenty-first step  221 , a check that a signal is received is made. If a signal is received, then the Signal B variable is set to the value “2” during a twenty-third step  223 . If no signal is received, then the Signal B variable is set to the value “0” during a twenty-fourth step  224 .  
         [0048]     At the end of the twenty-second step  222 , a check is made on whether a signal received corresponds to the channel previously received; if this is the case, the antenna has not moved and therefore it is fixed. If a signal is received, then the Signal B variable is set to the value “1” during a twenty-fifth step  225 . If no signal is received, then the Signal B variable is set to the value “2” during the twenty-third step  223 .  
         [0049]     If the Input B variable does not equal “1” or the twenty-third, twenty-fourth or twenty-fifth step  223  or  224  or  225  is finished, then a check is made on whether the Input C variable equals “1”. If the input C variable equals “1” then a twenty-sixth step  226  is carried out that selects the input C. Then, if the Signal C variable equals “0” a twenty-seventh step  227  is carried out, otherwise a twenty-eighth step  228  is carried out. The twenty-seventh step  227  is an azimuth scanning step of the same type as the second step  202 . The twenty-eighth step  228  consists of memorising the channel received then sending a motion command identical to the sixteenth step  216 .  
         [0050]     At the end of the twenty-seventh step  227 , a check that a signal is received is made. If a signal is received, then the Signal C variable is set to the value “2” during a twenty-ninth step  229 . If no signal is received, then the Signal C variable is set to the value “0” during a thirtieth step  230 .  
         [0051]     At the end of the twenty-eighth step  228 , a check is made on whether a signal received corresponds to the channel previously received; if this is the case, the antenna has not moved and therefore it is fixed. If a signal is received, then the Signal C variable is set to the value “1” during a thirty-first step  231 . If no signal is received, then the Signal C variable is set to the value “2” during the twenty-ninth step  229 .  
         [0052]     If the Input C variable does not equal “1” or the twenty-ninth, thirtieth or thirty-first step  229  or  230  or  231  is finished, then a check is made on whether the Input D variable equals “1”. If the input D variable equals “1” then a thirty-second step  232  is carried out that selects the input D. Then, if the Signal D variable equals “0” a thirty-third step  233  is carried out, otherwise a thirty-fourth step  234  is carried out. The thirty-third step  233  is an azimuth scanning step of the same type as the second step  202 . The thirty-fourth step  234  consists of memorising the channel received then sending a motion command identical to the sixteenth step  216 .  
         [0053]     At the end of the thirty-third step  233 , a check that a signal is received is made. If a signal is received, then the Signal D variable is set to the value “2” during a thirty-fifth step  235 . If no signal is received, then the Signal D variable is set to the value “0” during a thirty-sixth step  236 .  
         [0054]     At the end of the thirty-fourth step  234 , a check is made on whether a signal received corresponds to the channel previously received; if this is the case, the antenna has not moved and therefore it is fixed. If a signal is received, then the Signal D variable is set to the value “1” during a thirty-seventh step  237 . If no signal is received, then the Signal D variable is set to the value “2” during the thirty-fifth step  235 .  
         [0055]     If the Input D variable is not equal to “1” or the thirty-fifth, thirty-sixth or thirty-seventh step  235  or  236  or  237  is finished, then the second phase  200  ends and the third phase  300  can be carried out.  
         [0056]     The third phase  300  comprises a first part of formatting the detection realized during the first and second phases  100  and  200  then a second part of identifying the satellite channels as already known from the configuration information coming from the detection.  
         [0057]     As indicated above, if the Input B, Input C and Input D variables equal “0”, this means that there is no switch and therefore that the decoder is connected to an antenna that is fixed if the Signal A variable equals “1” or that is a motorised antenna if the Signal A variable equals “2”.  
         [0058]     In the other cases, this means that there is at least one antenna switch. It is possible to consider, systematically, a four-input switch as the instructions for a four-input switch are supported by two-input switches or to distinguish between the different cases possible: a two-input switch controlled at A and B or at A and C, two cascaded switches offering three inputs controlled at A-B-C or at A-C-D or at A-B-D, and one four-input switch or three cascaded two-input switches controlled at. A-B-C-D. The switches are identified according to Input A to D variables that are at “1” at the end of the second phase. For the inputs whose Input A to D variables are at “1”, it is sufficient to indicate that no antenna is connected to the input of the switch if the Signal A to D variable associated with the said input is equal to “0”, or to indicate that a fixed antenna is connected to the input of the switch input if the Signal A to D variable associated with the said input is equal to “1”, or even indicate that a motorised antenna is connected to the input of the switch if the Signal A to D variable associated with the said input is equal to “2”.  
         [0059]     Once the status of the antenna system is correctly updated, it is possible to move on to the identification of the satellites and channels. For fixed antennas, the entire satellite band is scanned according to a known technique to find all of the accessible channels, the channels are then memorized by indicating, if necessary, the switch control signal to be used to select it. For each motorised antenna, a rough scan of the satellite band is carried out while azimuth scanning with the antenna so as to identify the positions of the antenna that correspond to satellites according to a known technique, then for each satellite found, a satellite band scan is carried out to identify the channels. The channels are then memorized with the angular position of the antenna and possibly the switch input selection command.  
         [0060]     It is possible that the same channel can be accessed by several antennas, according to the channel memorisation interface, it is possible to make an automatic choice or to request the user if he wishes to memorize a single access to the channel or all the accesses.