CN1276652A - Self-inferring method of receiver for satellite broadcasting - Google Patents

Abstract

In a normal operation mode, a receiver Rx performs predetermined processing on a digital broadcasting signal from an artificial satellite to generate sound. The receiver Rx also executes a self-diagnostic mode as required. In the self-diagnostic mode, a controller 19 runs a diagnostic check as to whether an operating keypad 17 operates correctly. Further, the controller 19 runs a diagnostic check on the level of the receive sensitivity of the receiver Rx using C/N value. Through the use of an idle time in the above two diagnostic checks, the controller 19 checks whether each generated drive voltage is within each appropriate range; whether synchronization can be established in a PLL circuit 20 required for generating an intermediate-frequency signal S<SB>IF</SB>; whether synchronization can be established in a QPSK demodulator 21 required for QPSK-demodulating the intermediate-frequency signal S<SB>IF</SB>; whether the head of a reproduced master frame Beta can be detected correctly; and whether the head of a reproduced audio data frame Alpha can be detected correctly.

Description

The self-diagnosing method of the receiver that satellite broadcasting is used

The present invention relates to the receiver that satellite broadcasting is used, relate to the digital broadcast signal that common reception sends out from artificial satellite, that the receiver of output sound is carried out as required, diagnose this receiver itself whether unusual method takes place voluntarily.

In recent years, carrying out the planning that digital broadcasting is provided with artificial satellite.As this planning one of " global space " (World Space) with Africa, Asia and Central and South America as service area." global space " utilizes the fixed statellite that is transmitted into the sky, equator, provides sound programme to above-mentioned service area." global space " broadcasting one side's signal processing at first is described below.

(1) generates audio data frame α

At first, generate n way word voice data.Here, n is the natural number below 96 in " global space ".Each voice data is according to the standard of MPEG1 the 3rd audio layer (being designated hereinafter simply as MP3) digital compression in addition.Each voice data after the compression is encoded into T at regular intervals as shown in figure 18 ₁The frame that repeats.Generate n road audio data frame α thus.Each audio data frame α comprises CH synchronizing information, SCH (Service Control Header; Business is controlled prefix) and voice data.SCH illustrates the supplementarys such as content of voice data.SCH is added on each road voice data.But SCH represents itself to add the supplementary of the voice data of (promptly follow-up).The CH synchronizing information is added on the stem of each audio data frame α respectively, i.e. the front of SCH.The CH synchronizing information is the initial code of each audio data frame α, is made up of predetermined bit pattern (pattern).The sound that the voice data performance is corresponding with each road.

(2) error correction coding

Secondly, for the audio data frame α error correction that in above-mentioned (1), generates, carry out Reed Solomon Coding and Viterbi coding.

(3) generation of time division multiplexing and prime frame β

Then, with each audio data frame α time division multiplexing of encoding in above-mentioned (2).Then, the audio data frame α in multiple connection adds supplementary.Generate prime frame β thus.More particularly, each audio data frame α is divided into a plurality of shown in dotted line among Figure 19 (a).That is, each audio data frame α is divided into data block.Then, for example select the topped data block in stain zone of Figure 19 (a).Promptly select a data block respectively from each road audio data frame α.According to selected each data block, generate the prime frame β shown in Fig. 9 (b) again.Among Figure 19 (b), prime frame β comprises a selected n data block, frame synchronization information and FCH (Frame Control Header: frame control prefix).N Frame pressed the time shaft shape and arranged.FCH represents to discern the supplementarys such as information that each data block is used.Frame synchronization information is added on the stem of each prime frame β, i.e. the front of each FCH.Frame synchronization information is represented the starting position of prime frame β.

Generate a plurality of prime frame β as described above.But comprise the combination of mutually different data block among each prime frame β, for example, among Figure 19 (b), be drawn in the combination that comprises the data block that Figure 19 (a) stain zone covers in the prime frame β of high order end.Among Figure 19 (b), be drawn in the combination that comprises the data block that Figure 19 (a) hatched example areas covers among the prime frame β that left end plays the 2nd position again.

Again, each prime frame β is compiled into T at regular intervals shown in Figure 19 (b) ₂Repeat.

(4) QPSK (Quadrature Phase Shift Keying; Quadrature Phase Shift Keying) and send

Then, carry out digital modulation with each the prime frame β that generates in above-mentioned (3).Digital modulation mode is above-mentioned QPSK.More particularly, with 2 mutually orthogonal carrier waves of each prime frame β phase modulation.The signal of Sheng Chenging is as the digital broadcast signal S of L frequency range (1.5GHz frequency range) thus _DB, be sent to service area from fixed statellite.

Towards the receiver in " global space " to above-mentioned digital broadcast signal S _DBCarry out and the opposite processing procedure of broadcasting of a side, reproduce required voice data.Yet these receivers must be guaranteed the quality of certain level in the stage of dispatching from the factory.Therefore, producer carries out quality examination (operating state inspection) to receiver before dispatching from the factory facing.This quality examination is wished and can correctly be carried out at short notice.

Again, receiver breaks down in user's use sometimes.At this moment, near the maintenance center the user takes out of order receiver to etc. is located.The maintenance center is a fault of finding out receiver, checks the operating state of this receiver.The inspection of operating state is also wished can correctly carry out at short notice.

Use various inspection machines in the above-mentioned inspection again.Wherein a kind of is signal generator.Signal generator is connected in as the receiver of checking object, produces the above-mentioned digital broadcast signal S of simulation _DBSignal S _SUMThe examiner is with reference to input analog signal S _SUMThe action of receiver, seek the exception of this receiver as possible.Yet checkout facility, especially signal generator are very expensive.Therefore, signal generator is not wanted to purchase from reducing the viewpoint of equipment investment in some maintenance center.Therefore with regard to hope the undesired signal generator is arranged and can diagnose self unusual receiver.

Therefore, the object of the present invention is to provide whether normally receiver of the each several part of can be reliably and diagnosing constitution equipment itself at a high speed.Another object of the present invention is to provide the normal or unusual receiver of each that does not need the great number equipment investment and can diagnose constitution equipment itself.

Realize above-mentioned each purpose by following each invention, solve above-mentioned existing problems.Below each invention have a hereinafter described technique effect.

The 1st invention receives the digital broadcast signal that sends out from artificial satellite usually for a kind of self-diagnosing method, and is that the receiver of output sound is carried out as required, diagnose this receiver itself whether unusual method takes place voluntarily,

Time division multiplexing is the audio data frame of the voice data generation of way according to the rules, and constitute prime frame according to the audio data frame of multiplexing gained, use the prime frame that is constituted that carrier wave is carried out QPSK (Quadrature Phase ShiftKeying: Quadrature Phase Shift Keying) modulation, thereby generation digital broadcast signal again; This self-diagnosing method comprises:

Diagnosis drives each driving voltage that receiver uses whether in suitable scope, and the 1st outside diagnosis algorithm of this diagnostic result notice,

To the input signal of receiver is mixed with local oscillation output, can the PLL circuit that generating the down-conversion of intermediate-freuqncy signal needs correctly be established synchronously and diagnose, and the 2nd diagnosis algorithm of this diagnostic result notice outside,

The intermediate-freuqncy signal that down-conversion is generated is carried out the QPSK demodulation, reappears the qpsk demodulator that needs in the QPSK demodulation process of prime frame and whether correctly establish and diagnoses synchronously, and the 3rd outside diagnosis algorithm of this diagnostic result notice,

To in the frame synchronization process that detects the stem of utilizing the prime frame that the QPSK demodulation process reproduces, whether correctly detect this stem and diagnose, and the 4th outside diagnosis algorithm of this diagnostic result notice,

To being according to after the reproducing audio data frame with each prime frame of utilizing frame synchronization process to detect stem, detect in the channel Synchronous Processing of stem of audio data frame of reproduction, whether correctly detect this stem and diagnose, and the 5th outside diagnosis algorithm of this diagnostic result notice,

To the 6th diagnosis algorithm of whether correctly working and diagnosing as the operation keys of user interface, and

C/N value (the Carrier to Noise Ratio of the intermediate-freuqncy signal of repeated detection input qpsk demodulator; Carrier signal-noise ratio), calculate the mean value of detected each C/N value, according to the 7th diagnosis algorithm of the quality of the receiving sensitivity of the mean value that calculates diagnosis receiver,

The the 1st～the 5th diagnosis algorithm utilizes the time of vacating in the 6th and the 7th diagnosis algorithm to carry out respectively.

In the 1st invention, receiver is implemented the 1st～the 7th diagnosis algorithm for unusual part is carried out self diagnosis.At the 6th diagnosis algorithm, because the requirement of people's keyboard operation, receiver promptly allows to high-speed action, also essential wait keyboard operation.And at the 7th diagnosis algorithm, for the correct quality of the receiving sensitivity of change at every moment of diagnosing, must be every C/N value of time detecting of a certain length.Therefore receiver obtains the before essential standby of next C/N value after obtaining the C/N value.Therefore, suppose that receiver is in holding state easily under the situation of just implementing the 6th diagnosis algorithm and the 7th diagnosis algorithm, just produce idle time of receiver (vacant time just).Therefore, if adopt the 1st invention, can utilize the vacant time that in the 6th diagnosis algorithm and the 7th diagnosis algorithm, produces to implement the 1st diagnosis algorithm～the 5th diagnosis algorithm, so receiver can effectively utilize the time and implement many diagnostic process.By means of this, whether receiver can diagnose the each several part that constitutes self normal at a high speed.

Again, the each several part that receiver constitutes self in each diagnosis algorithm automatic diagnosis is normally or unusual, and this diagnostic result notice is outside.By means of this, the examiner can understand the unusual place of receiver reliably.

The 2nd invention is subordinated to the 1st invention, and its receiver can connect the signal generator of the signal that the analog digital broadcast singal takes place,

Use the input signal of the analog signal of signal generator generation in the 2nd diagnosis algorithm as receiver.

As is generally known signal generator uses when carrying out tight inspection through being everlasting.Whether the analog signal that receiver basis signal generator generates in the 2nd invention produces the each several part that constitutes self and to carry out deagnostic test unusually.By means of this, whether unusually the each several part that receiver can be diagnosed formation itself more reliably.

The 3rd invention is subordinated to the 1st invention, and its receiver can connect antenna for receiving digital broadcast signal,

In the 2nd diagnosis algorithm,, use digital broadcast signal by the antenna input as the input signal of receiver.

The common receiving digital broadcast signal of receiver, output sound.In the 3rd invention, whether receiver uses the inside of digital broadcast signal diagnosis receiver own to take place unusually.Therefore, receiver does not use at the very expensive signal generator of price described in the 2nd invention, can implement each diagnosis algorithm.By means of this, can cut down the equipment investment of necessity relevant with receiver.

These and some other purpose, feature, form and advantage of the present invention more clearly show in will the present invention will be described in conjunction with the accompanying drawings below.

Fig. 1 is the block diagram of the general structure of the related receiver Rx of expression the present invention the 1st embodiment.

Fig. 2 is the flow chart of the processing procedure of presentation graphs 1 control part 19 execution.

Fig. 3 is the flow chart of the processing procedure of presentation graphs 1 control part 19 execution.

Fig. 4 is the flow chart of the processing procedure of presentation graphs 1 control part 19 execution.

Fig. 5 is the flow chart of detailed process process of the step S8 of presentation graphs 3.

Fig. 6 is the flow chart of detailed process process of the step S10 of presentation graphs 3.

Fig. 7 is the flow chart of detailed process process of the step S12 of presentation graphs 3.

Fig. 8 is the flow chart of detailed process process of the step S14 of presentation graphs 3.

Fig. 9 is the flow chart of detailed process process of the step S15 of presentation graphs 3.

Each pattern shown in the state of the mode of operation selector 16 of Figure 10 presentation graphs 1.

Figure 11 is used for the operation keys 17 of key diagram 1.

Figure 12 be used for key diagram 3 grades when shown in processing procedure, the sign F that the control part 19 of Fig. 1 uses ₁₄, F ₂₀, F ₂₁, F _FRAME

The content that the display 18 of Figure 13 presentation graphs 1 is shown.

Figure 14 is the block diagram of detailed structure of the voltage detector 15 of presentation graphs 1.

An example of the transition of each diagnosis algorithm of Figure 15 presentation graphs 2～shown in Figure 9.

Figure 16 is a block diagram of partly expressing the receiver Rx under the situation that possesses BER detector 17.

Figure 17 represents the relation of C/N value and BER.

Figure 18 represents the data structure of audio data frame α.

Figure 19 represents generation method and the data structure thereof of prime frame β.

Fig. 1 is the block diagram of the general structure of the related receiver Rx of expression the present invention one example.Among Fig. 1, receiver Rx has input terminal 1, tuner 2, PLL synchronizing indicator 3, QPSK demodulation section 4, CH decoding part 5, MPEG decoder 6, D/A converter 7, low frequency amplifier 8, loud speaker 9, quiet usefulness the 1st switch 10, power supply 11, power supply with the 13, the 2nd stabilized power supply portion 14 of the 2nd switch the 12, the 1st stabilized power supply portion, voltage detector 15, mode of operation selector 16, operation keys 17, display 18 and control part 19.

Tuner 2 comprises PLL circuit 20.Tuner 2 also comprises other various structures, but does not have direct relation in itself with the distinctive self diagnostic mode of the application (will narrate below).Therefore the structure beyond the PLL circuit is omitted in diagram.

QPSK demodulation section 4 comprises qpsk demodulator 21, QPSK synchronizing indicator 22 and C/N detector 23.

CH decoding part 5 comprises CH decoder 24, frame sync detector 25 and CH synchronizing indicator 26.

Control part 19 is controlled " self diagnostic mode that factory uses " as described below, " routine work pattern ", " self diagnostic mode that maintenance service is used " according to the processing procedure work shown in the flow chart of Fig. 2～Fig. 9.

1. the self diagnostic mode used of factory

At first, the examiner of factory carries out the preparation of the self diagnostic mode that factory uses in the quality examination in the stage of dispatching from the factory.At this moment, connect signal generator (not expressing among the figure) on the input terminal 1 of Fig. 1.

Below mode of operation selector 16 is illustrated.Mode of operation selector 16 has 2 switch (not shown)s and 2 terminal A and B (consulting Fig. 1).In 2 switches one is connected with terminal A, and another switch is connected with terminal B.2 switches carry out the on/off operation, and above-mentioned 3 kinds of patterns utilize the combination of this break-make to represent as shown in figure 10.Also have, among Figure 10, the switch that is connected with terminal A is designated as switch A, and the switch that is connected with terminal B is designated as out B.And A blocking-up of " 0 " expression derailing switch or switch B blocking-up, " 1 " expression switch A conducting or switch B conducting.

1. switch A is " 1 " (conducting), and switch B means the self diagnostic mode that factory uses when being " 0 " (blocking-up).2. switch A is " 0 " (blocking-up), and switch B means the self diagnostic mode that maintenance service is used when being " 1 " (conducting).When 3. switch A and B are " 1 " (conducting), mean the routine work pattern.

The examiner operates above-mentioned mode of operation selector 16, as the pattern of carrying out from now on, is set at receiver Rx and carries out factory's self diagnostic mode.

And for example fruit is set at conducting to the 2nd switch among Fig. 1, then power source voltage Vcc is offered the 2nd stabilized power supply portion 14.In the 2nd stabilized power supply portion 14, generate driving voltage Vt, Va and Vd according to the power source voltage Vcc that provides.Driving voltage Vt makes tuner 2 work.Driving voltage Va makes QPSK demodulation section 4 and 7 work of D/A converter.Driving voltage Vd makes CH decoding part 5 and 6 work of MPEG decoder.With this receiver Rx is started working.

Again, do not need output sound in the self diagnostic mode that factory uses, therefore,, make 10 blocking-up of the 1st switch at current time.As a result, do not drive low frequency amplifier 8, thereby receiver Rx is in mute state.

In a single day above preparation is finished, and control part 19 is just judged the pattern of this less important execution.Promptly read the switch A of mode of operation selector 16 and the state of B (the step S1 of Fig. 2).Control part 19 judges whether the state of the mode of operation selector 16 that reads represents the self diagnostic mode (step S2) that factory uses.In the current moment, the self diagnostic mode that this state representation factory uses, thereby control part 19 enters step S3.On the other hand, under the situation beyond the pattern that factory uses, control part 19 enters following step S22.

At the storage area that receiver Rx has, prepare end mark F shown in Figure 11 in advance ₁₄, F ₂₀, F ₂₁And F _FRAMEF ₁₄Be set at " 0 " or " 1 " by control part 19, represent that whether the diagnosis algorithm of the 2nd stabilized power supply portion 14 finishes.Equally, end mark F ₂₀Whether the diagnosis algorithm of expression PLL circuit 20 finishes.End mark F ₂₁Whether the diagnostic markers of expression qpsk demodulator 21 finishes.End mark F _FRAMEWhether the diagnosis algorithm of the frame synchronization process of expression CH decoder 24 finishes.

Control part 19 step S3 shown in Figure 11 (a) with each end mark F ₁₄, F ₂₀, F ₂₁And F _FRAMEBe set at " 0 " (step S3).Represent that with this any diagnosis algorithm does not all have to finish.

Present description operation key 17.Shown in Figure 12 (a), operation keys 17 comprises various keys.In order to constitute these keys, adopt connector, or weld.But, in the stage of dispatching from the factory the connector loose contact taking place sometimes, or welds not good enough situation.There is this unusual receiver Rx not dispatch from the factory.For this reason, control part 19 needs diagnostic operation key 17 normal or unusual.So control part 19 is carried out the diagnosis algorithm of following operation keys 17.

1-1. the diagnosis algorithm of operation keys 17

In this diagnosis algorithm, control part 19 at first shows predetermined information on display 18, impel the examiner to operate whole keys.The examiner responds to information, operates each key.Operation keys 17 produces the signal of the key of identifying operation.Control part 19 is got the into input signal of operated key (step S4).Be that control part 19 receives the signal that operation keys 17 produces.Control part 19 is discerned the key of being operated, and show (step S6) on display 18 under the situation of having got into the key input (step S5).For example, shown in Figure 12 (b), during examiner's operation " B " key, operation keys 17 produces the signal S of identification " B " key _BThe signal S that is produced _BBe Controlled portion 19 gets into.The signal S that control part 19 identifications are taken into _B, and the information that display operation " B " key will be expressed on display 18.Also have, in Figure 12 (b), the key of having operated represents that with solid line Cao Zuo key is not represented with point.

Control part 19 or is not taken in step 5 under the situation of key input after step S6 finishes, and the diagnosis from key 17 temporarily is separated from, and enters the step S7 of Fig. 3.Then, control part 19 judges whether the diagnosis algorithm of the 2nd stabilized power supply portion 14 has carried out (step S7).At step S7, control part 19 is with reference to above-mentioned end mark F ₁₄At this constantly, end mark F ₁₄Be still later " 0 " of sign S3, therefore, the diagnosis algorithm that control part 19 is judged as the 2nd stabilized power supply portion 14 does not execute as yet, enters step S8 then.

1-2. the diagnosis algorithm of the 2nd stabilized power supply portion 14

For tuner 2 is correctly worked, be necessary to make its operating voltage to be in the suitable scope.The minium operation voltage value of now supposing tuner 2 is V _MIN1, its higher limit is V _MAX1Under this supposition, the driving voltage Vt that supplies with tuner 2 must satisfy V _MIN1≤ Vt≤V _MAX1Equally, driving voltage Va and Vd must satisfy V _MIN2≤ Va≤V _MAX2And V _MIN3≤ Vd≤V _MAX3

In this example, for convenience, it is identical with the operating voltage of D/A converter 7 to get QPSK demodulation section 4, but two operating voltages are not limited to identical.This condition also is applicable to CH decoding part 5 and MPEG decoder 6 operating voltages.

Yet driving voltage Vt, Va or Vd do not satisfy V sometimes _MIN1≤ Vt≤V _MAX1, V _MIN2≤ Va≤V _MAX2Or V _MIN3≤ Vd≤V _MAX3That is, the 2nd stabilized power supply portion 14 can not produce correct driving voltage Vt, Va and Vd sometimes.Exist this unusual receiver Rx to dispatch from the factory.

Therefore, the diagnosis algorithm of the 2nd stabilized power supply portion 14 of receiver Rx execution in step S8.At this diagnosis algorithm, utilize the testing result of voltage detector 15.Voltage detector 15 has switch 27 and A/D converter 28 as shown in figure 13.Switch 27 is connected with the 2nd stabilized power supply portion 14.Switch 27 optionally receives the voltage of control part 19 appointments among driving voltage Vt, Va and the Vd, and intactly outputs to A/D converter 28.A/D converter 28 is driving voltage Vt, the Va of analog quantity of input or the voltage that Vd is transformed to digital quantity, i.e. in addition digitlization.Control part 19 is got driving voltage Vt, Va after the into digitlization or Vd as testing result.

Be illustrated below with reference to flow chart shown in Figure 5 detailed process process this diagnosis (the step S8 of Fig. 3).In the step S81 of Fig. 5, the switch 27 of control part 19 switched voltage detectors 15 is specified some among driving voltage Vt, Va and the Vd.Make driving voltage Vt, the Va of appointment and Vd intactly import A/D converter 28 with this by switch 27.A/D converter 28 is with driving voltage Vt, Va and the in addition digitlization of Vd of input.Then, control part 19 is taken into driving voltage Vt, Va and the Vd (step S81) after the digitlization.

Then, judge whether driving voltage Vt, the Va and the Vd that are taken into satisfy inequality V _MIN1≤ Vt≤V _MAX1, V _MIN2≤ Va V _MAX2Or V _MIN3≤ Vd≤V _MAX3(step S82).When not satisfying inequality, control part 19 " VOLT NG " (" electric voltage exception ") shown in Figure 14 (a) is such, shows the unusual information (step S83) of driving voltage that the second stabilized power supply portion 14 generates on display 18.

For example, specify driving voltage Vt in step S81 hypothesis.Under this assumption, whether the driving voltage Vt after step S82 judges digitlization satisfies inequality V _MIN1≤ Vt≤V _MAX1When not satisfying this inequality,, notify examiner the 2nd stabilized power supply portion 14 unusual at step S83.

And, when satisfying inequality, judge whether to specify whole driving voltage Vt, Va and Vd (step S84) in step 82.When having unspecified driving voltage, control part 19 returns step S81, specifies unselected driving voltage Vt, Va and Vd, proceeds this diagnosis algorithm.

On the other hand, when having specified whole driving voltage Vt, Va and Vd, the 2nd stabilized power supply portion 14 is normal, and control part 19 is judged as and makes this diagnosis algorithm finish also can.Therefore, end mark F ₁₄Shown in Figure 11 (b), be set in " 1 " (step S85), with this meaning of representing to make the diagnosis algorithm of the 2nd stabilized power supply portion 14 to finish.Then, carry out the preparation (step 86) of the diagnosis algorithm of following PLL circuit 20.In step 86, the not shown timer that goes out is resetted, i.e. setting-up time t _EBe 0, timer begins minute t _EIn case step S86 finishes, control part 19 just makes the diagnosis algorithm of the 2nd stabilized power supply portion 14 finish, and the step S8 of Fig. 3 is finished.

In the above, this diagnosis algorithm judges whether driving voltage Vt, Va and Vd enter suitable scope.Display 18 notifies examiner the 2nd stabilized power supply portion 14 to have unusually when detecting not at driving voltage Vt, the Va of OK range and Vd.Thus, the examiner can forbid existing unusual receiver Rx to dispatch from the factory.

In case step S8 finishes, control part 19 just returns the step S4 of Fig. 2, i.e. the diagnosis algorithm of operation keys 17.Therefore, the examiner key is operated, and when the input of operation keys 17 is arranged, the key of operating is shown in display 18 (step S4～S6).Thereafter, control part 19 is with reference to end mark F ₁₄, judge the whether executed intact (Fig. 3, step S7) of diagnosis algorithm of the 2nd stabilized power supply portion 14.Because end mark F ₁₄At step S85 is later on " 1 ", and control part 19 judges that the diagnosis algorithm executed of the 2nd stabilized power supply portion 14 is intact, enters step S9.Then, control part 19 is judged the whether executed intact (step S9) of diagnosis algorithm of PLL circuit.At step S9, control part 19 is with reference to described end mark F ₂₀, at this constantly, end mark F ₂₀Keep step S3 later " 0 " constant, so control part judge that the diagnosis algorithm of PLL circuit 20 does not execute as yet, enters step S10.

1-3.PLL the diagnosis algorithm of circuit 20

Signal generator is connected on the input terminal 1.Signal generator produces described digital broadcast signal S _DBAnalog signal S _SUMAnalog signal S _SUMBe prime frame β (with reference to Figure 19 (b)) to phase place each other 2 carrier waves of orthogonality relation modulate the result of (QPSK modulation).Analog signal S _SUMBe input to tuner 2 by input terminal 1.In tuner 2 with the input analog signal S _SUMLocal oscillation output mixing with voltage-controlled oscillator etc. makes this analog signal S _SUMDown-conversion is transformed to intermediate-freuqncy signal S with this _IFUtilize PLL circuit 20 to make the frequency of local oscillation output and phase place synchronous with the reference frequency and the reference phase of not shown generations such as quartz (controlled) oscillator.The time of hereinafter PLL circuit 20 having been started working till foundation synchronously is called phase-locked time t _L1Make the receiver Rx real-world operation of manufacturing, then can obtain lock phase time t _L1This time is t fiducial time _R1The basis.Phase-locked time t _L1Add required time margin t _M1(t _M1＞0) t in the time of, then can obtaining benchmark _R1For example, select t _L1As t _M1The time, t _R1Equal 2*t _L1Therefore, normal PLL circuit 20 is at t fiducial time _R1During in must set up synchronously.

But PLL circuit 20 also produces fault in the quality examination stage sometimes.Out of order PLL circuit 20 can not begin to t fiducial time in its work _R1Till during set up synchronously.Receiver Rx with out of order PLL circuit 20 is not suitable for dispatching from the factory.

Therefore, the diagnosis algorithm of the PLL circuit 20 of receiver Rx execution in step S10.Use the testing result of PLL synchronizing indicator 3 in this diagnosis algorithm.PLL synchronizing indicator 3 is connected with PLL circuit 20.Whether PLL synchronizing indicator 3 detects in the PLL circuit 20 has set up synchronously.Measure and set up when synchronous, from the testing result of synchronizing indicator 3 these situations of output expression.Control part 19 is got into this testing result.

Below with reference to flow chart shown in Figure 6, the detailed process process of this diagnosis algorithm (the step S10 of Fig. 3) is illustrated.In Fig. 6, at first judge the current self diagnostic mode (step S101) that maintenance service is used of whether carrying out.Owing to currently carrying out the self diagnostic mode that factory uses, control part 19 enters step S102.And when carrying out the self diagnostic mode that maintenance service uses, control part 19 enters step S108 described later.

Suppose described analog signal S _SUMBe included in frequency f _C1Band occupancy B for centre frequency _C1In.Again, the examiner operates operation keys 17, selects input analog signal S _SUMBand occupancy B _C1Operation keys 17 is according to examiner's input, identification band occupancy B _C1Signal S _C1Send to control part 19.Control part 19 is according to the signal S of this reception _C1Output frequency control data D _FREQ(step S102) is set in band occupancy B with this frequency acceptance band through tuner 2 _C1Consequently, tuner 2 begins to receive analog signal S _SUM, carry out above-mentioned down-conversion.

Then, get the into testing result of PLL synchronizing indicator 3 (step S103).Control part 19 judges whether set up (step S104) synchronously in the PLL circuit 20 according to the testing result of getting into.

Do not set up when synchronous, control part 19 is removed t fiducial time in predetermined storage area storage _R1And control part 19 also obtains the value t of the current indication of timer _Et _EBe to finish elapsed time from step S86 (with reference to Fig. 5).Control part 19 is with t fiducial time _R1With elapsed time t _ECompared, judged whether t _E＞t _R1(step S105).

Not t _E＞t _R1The time, at t fiducial time _R1During in perhaps set up synchronously at PLL circuit 20, therefore, temporary transient these diagnosis algorithms that break away from of control part 19 return the diagnosis algorithm of aforesaid operations key 17.At this moment, when the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 after the step S7 of execution graph 3 with reference to end mark F ₂₀, judged whether to carry out the diagnosis algorithm (step S9) of PLL circuit 20.Because end mark F ₂₀Be 0, carry out the diagnosis algorithm (step S10) of PLL circuit 20 once again.

On the other hand, at step S105, be t _E＞t _R1The time, expression PLL circuit 20 is at t fiducial time _R1During in set up synchronously.Be that PLL circuit 20 is unusual.Therefore, " PLL NG ' (" PLL is unusual ") is such, shows the information (step S106) that PLL circuit 20 is unusual on display 18 shown in Figure 14 (b) for control part 19.

As indicated above, adopting the diagnosable PLL circuit 20 of this diagnosis algorithm is normally or unusual.Measure PLL circuit 20 when unusual, display 18 is notified the examiner this situation.By means of this, the examiner forbids having so unusual receiver Rx to dispatch from the factory.

Again, at step S104, established under the synchronous situation, the PLL circuit judges is normal, is judged as again to make diagnosis algorithm finish also can.Therefore, end mark F ₂₀Shown in Figure 11 (c), be set at " 1 ", (step S107).Carry out the preparation (step S108) of the diagnosis algorithm of next qpsk demodulator 21 once again, that is to say, control part 19 makes timer begin minute t _EIn case step S108 finishes, control part 19 just breaks away from the diagnosis algorithm of PLL circuit 20.

In case above-mentioned steps S10 finishes, control part 19 just returns the step S4 of Fig. 2.When the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 is because end mark F ₁₄And end mark F ₂₀Be respectively " 1 ", enter step S11.Control part 19 is with reference to above-mentioned end mark F ₂₁, judged whether to carry out the diagnosis algorithm (sign S11) of qpsk demodulator 21.At current time, because this end mark F ₂₁Be " 0 ", control part 19 is judged as this diagnosis algorithm and does not carry out, and control part 19 enters step S12.

1-4.QPSK the diagnosis algorithm of demodulator 21

Among Fig. 1, at qpsk demodulator 21 input signal S _IF21 couples of input signal S of qpsk demodulator _IFCarry out synchronous demodulation (synchronous detection), promptly carry out the QPSK demodulation.Reproduce baseband signal S thus _BB, i.e. prime frame β (consulting Figure 19 (b)).Above-mentioned synchronous demodulation is also identical with down-conversion in the tuner 2.Therefore, also there is PLL circuit (another circuit different with PLL circuit 20) inside of qpsk demodulator 21.Promptly in qpsk demodulator 21, also make the frequency of local oscillation output and the frequency and the Phase synchronization of the reference signal that phase place and quartz (controlled) oscillator etc. are exported.Here, will be called phase-locked time t from the time that qpsk demodulator 21 work begins till set up synchronously _L2Make the receiver Rx real-world operation of manufacturing, then can obtain phase-locked time t _L2Phase-locked time t _L2Be t fiducial time _R2The basis.With t fiducial time _R1Identical, phase-locked time t _L2Add required time surplus t _M2, can get t fiducial time _R2

But, beginning to t fiducial time from qpsk demodulator 21 work _R2Till during do not set up when synchronous, this qpsk demodulator 21 has fault.Receiver Rx with the qpsk demodulator 21 that breaks down is not suitable for dispatching from the factory.Therefore, the diagnosis algorithm of the qpsk demodulator 21 of control part 19 implementation step S12.In this diagnosis, utilize the testing result of QPSK synchronizing indicator 22.Realize QPSK synchronizing indicator 22 with the structure identical with PLL synchronizing indicator 3.QPSK synchronizing indicator 22 is connected with qpsk demodulator 21.Whether QPSK synchronizing indicator 22 detects sets up at qpsk demodulator 21 synchronously.Set up when synchronous, QPSK synchronizing indicator 22 produces the testing result of these situations of expression.Control part 19 is got into this testing result.

Be illustrated below with reference to flow chart shown in Figure 7 detailed process process this diagnosis algorithm (the step S12 of Fig. 3).In Fig. 6, control part 19 is taken into the testing result (step S121) of QPSK synchronizing indicator 22.Control part 19 judges whether the testing result of getting into represents to have set up in the QPSK synchronizing indicator 22 (step S122) synchronously.Do not set up when synchronous, control part 19 takes out t fiducial time of the storage area that is stored in regulation in advance _R2Control part 19 also obtains the value t of timer _ENumerical value t _EBe that finish time with step S108 is as the elapsed time of starting at a little.Thereafter, with t fiducial time _R2With elapsed time t _ECompared, judged whether t _E＞t _R2(step S123).

Not t _E＞t _R2The time, control part 19 temporarily breaks away from these diagnosis algorithms, returns the step S4 of Fig. 2.Therefore, when the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 is after the step S7 and step 9 of execution graph 3, because end mark F ₂₁Not " 0 ", return the diagnosis algorithm (step S12) of QPSK.

On the other hand, at step S123, be t _E＞t _R2The time, expression qpsk demodulator 21 is at t fiducial time _R2In set up synchronously.Therefore, control part 19 " QPSK NG " (QPSK is unusual) shown in Figure 14 (c) is such, shows the information (step S124) that qpsk demodulator 21 is unusual on display 18.

Utilize this diagnosis algorithm, it is normally or unusual that control part 19 can be diagnosed qpsk demodulator 21.When to measure qpsk demodulator 21 be unusual, display 18 was notified the examiner this situation, and in view of the above, the examiner can forbid having so unusual receiver Rx dispatches from the factory.

Again, it is normal to establish under the synchronous situation qpsk demodulator 21 at step S122, so control part 19 is judged as and finishes this diagnosis algorithm and also can.Therefore, end mark F ₂₁Shown in Figure 11 (d), be set at " 1 " (step S125).Carry out the preparation (step S126) of the synchronous diagnosis algorithm of next frame again.Just timer begins to measure t _EThen carry out the preparation (step S127) of diagnosis algorithm of the receiving sensitivity of back.In the diagnosis algorithm of receiving sensitivity, use by C/N detector 23 detected C/N values.Because the C/N value is at every moment changing, so receiver Rx repeatedly measures the C/N value, calculates its mean value C/N _AVEIn order to calculate the mensuration number of times, in receiver Rx, set counter (not shown go out).At step S127, with the value i of counter _C/NBe set at " 0 ".In case step S127 finishes, control part 19 just breaks away from from this diagnosis algorithm (the step S12 of Fig. 3).

In case above-mentioned steps S12 finishes, control part 19 just returns the step S4 of Fig. 2.Therefore, when the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 execution in step S7, S9 and S11 enter step S13.Control part 19 is with reference to end mark F _FRAME, whether the diagnosis algorithm of judgment frame Synchronous Processing has implemented (step S13).At current time, end mark F _FRAMEBe " 0 ", so control part 19 judges that the diagnosis algorithm of the frame synchronization process of CH decoder 24 not implemented, and enters step S14.

1-5.CH the diagnosis algorithm of decoder 24

As shown in Figure 1, will import CH decoder 24 successively by the prime frame β (baseband signal SBB) that qpsk demodulator 21 reproduces.The stem of each the prime frame β that imports in order to discern detects frame synchronization information (consulting Figure 19 (b)) from this prime frame β.Hereinafter should detect to handle and be called frame synchronization process.To be called t lock in time from CH decoder 24 start frame Synchronous Processing to the time of setting up till the frame synchronization _FSLock in time t _FSAs long as the receiver Rs actual operation of manufacturing just can be accessed.Lock in time t _FSBe t fiducial time _R3The basis.Fiducial time t _R3With t fiducial time _R1The same, lock in time t _FSAdd required time surplus t _M3Just can obtain.

But, beginning to play t fiducial time from work _R3Till during can not set up under the situation of frame synchronization, CH decoder 24 has fault.Receiver Rx with the decoder 24 that breaks down is not suitable for dispatching from the factory.

Therefore, the diagnosis algorithm of the frame synchronization process of control part 19 execution in step S14.In this diagnosis algorithm, utilize the testing result of frame sync detector 25.Frame sync detector 25 is connected with CH decoder 24, and frame synchronization detects 25 these CH decoders 24 of detection and whether sets up frame synchronization.In case the frame synchronization of foundation, the just testing result of this situation of generation expression.Control part 19 is got into this testing result.

1-5-1. the diagnosis algorithm of frame synchronization

Be illustrated below with reference to flow chart shown in Figure 8 detailed process process this diagnosis algorithm (the step S14 of Fig. 3).In Fig. 8, control part 19 is taken into the testing result (step S141) of C/N detector 23, remains in inner storage area.Then, the value i of counter _C/NIncrease " 1 " (step S142)., it should be noted that step S141 and step S142 are the steps that is contained in the diagnosis algorithm of receiving sensitivity here.If after qpsk demodulator 21 is established synchronously, then can detect the C/N value.Therefore, in this example, step S141 and step S142 carry out after the diagnosis algorithm of qpsk demodulator 21 immediately.That is to say, make receiving sensitivity diagnosis algorithm the zero hour as early as possible.As a result, the end of the diagnosis algorithm of receiving sensitivity is the fastest.Like this, the diagnostic mode used of factory just can carry out with the short time.

After step S142, control part 19 obtains the testing result (step S143) of frame sync detector 25.Control part 19 then judges whether set up frame synchronization (step S144) at CH decoder 24 according to the testing result that obtains.When not setting up frame synchronization, control part 19 takes out t fiducial time that deposits in advance in the memory block of regulation _R3And then control part 19 obtains the value t of timer _Et _EValue for concluding time of step S126 as the elapsed time of starting at a little.With t fiducial time _R3With elapsed time t _ECompared, judged whether t _E＞t _R3(step S145).

Not t _E＞t _R3The time, control part 19 temporarily breaks away from from this diagnosis algorithm, returns the step S4 of Fig. 2, and therefore, when the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 returns the diagnosis algorithm (step S14) of frame synchronization process after step S7, S9, S11 and the S13 of execution graph 3.

On the other hand, at step S145, be t _E＞t _R3Situation under, expression CH decoder 24 is at t fiducial time _R3Can not set up frame synchronization with interior.In this case, control part 19 distinguishes that CH decoder 24 has fault, and " FRAME NG " (" frame is unusual ") is such shown in Figure 14 (d), shows the unusual information (step S146) of frame synchronization process of CH decoder 24 on display 18.As mentioned above, in this diagnosis algorithm, detect frame synchronization process when unusual, display 18 is notified the examiner this situation.In view of the above, the examiner can forbid having so unusual receiver Rx to dispatch from the factory.

Again, in step S144, under the situation that frame synchronization is established, because frame synchronization process is normal, even control part 19 is judged as and finishes this diagnosis algorithm and also can.Therefore, end mark F _FRAMEShown in Figure 11 (e), be set at " 1 ", (step S147).Control part 19 carries out the preparation (step S148) of the synchronous diagnosis algorithm of the channel of back again.That is to say that timer begins minute t _EThe examiner operation keys 17 is operated, the selective reception channel is imported.Operation keys 17 response examiners' input sends the signal S that discerns receiving channels to control part 19 _CH Control part 19 at step S148 again according to this received signal S _CHGenerate the CH control data D that the identification receiving channels is used _CHCH control data D _CHBe sent to CH decoder 24.By means of this, the audio data frame α that identification should be reproduced in the audio data frame that each prime frame β (with reference to Figure 19 (b)) is comprised.

In case step S148 finishes, control part 19 just breaks away from from the diagnosis algorithm of frame synchronization process.In case the S14 of Fig. 3 finishes, control part just returns the step S4 of Fig. 2.Therefore, when the examiner carried out key operation and input from operation keys 17 is arranged, display 18 showed operated key (step S4～S6).Thereafter, control part 19 execution in step S7, S9 and S11, thereafter, because end mark F _FRAMEBe " 1 ", enter step S15.

1-5-2. the diagnosis algorithm that channel is synchronous

Specified receiving channels as mentioned above at CH decoder 24.CH decoder 24 is selected the data block of receiving channels from each prime frame β of input.CH decoder 24 is arranged the data block exchange of selecting, reproducing audio data frame α (with reference to Figure 19 (a)), and then, CH decoder 24 detects the CH synchronizing information that this audio data frame α (with reference to Figure 18) comprises in order to discern the stem of audio data frame α.Claim that below this detection is treated to the channel Synchronous Processing.CH decoder 24 outputs to MPEG decoder 6 with audio data frame α from stem according to detected CH synchronizing information.The time that the channel Synchronous Processing that begins CH decoder 24 to carry out plays till channel is set up synchronously is called t lock in time _CSMake that the receiver Rx that produces is actual to carry out work and just can access t lock in time _CSLock in time t _CSBe t fiducial time _R4The basis.Fiducial time t _R4With t fiducial time _R1The same, can be by t lock in time _CSRequired in addition time margin t _M4Obtain.

But, begin to t fiducial time from work _R4Till during fail to set up under the synchronous situation, CH decoder 24 has fault.Receiver Rx with the CH decoder 24 that has fault is not suitable for dispatching from the factory.

Therefore, the synchronous diagnosis algorithm of channel of control part 19 execution in step S15.In this diagnosis algorithm, utilize the testing result of CH synchronizing indicator 26.Here, CH synchronizing indicator 26 is connected with CH decoder 24, and it is synchronous whether detection CH decoder 24 sets up channel.In case it is synchronous to set up channel, CH synchronizing indicator 26 just produces the testing result of this situation of expression.Control part 19 is got into this testing result.

Be illustrated below with reference to flow chart shown in Figure 9 detailed process process this diagnosis algorithm (the step S15 of Fig. 3).In Fig. 9, control part 19 is taken into the testing result (step S151) of C/N detector 23, remains in inner storage area.Then, the value i of counter _C/NIncrease " 1 " (step S152).Step S151 and step S152 are also the same with step S141 and step S142, be contained in receiving sensitivity diagnosis algorithm step.

Thereafter, control part 19 obtains the testing result (step S153) of CH synchronizing indicator 26.Control part 19 judges according to the testing result that obtains whether CH decoder 24 sets up channel (step S154) synchronously.Do not setting up channel when synchronous, control part 19 takes out t fiducial time that deposits in advance in the memory block of regulation _R4And then control part 19 obtains the value t of timer _Et _EValue for concluding time of step S148 as the elapsed time of starting at a little.With t fiducial time _R4With elapsed time t _ECompared, judged whether t _E＞t _R4(step S155).

At t _E＞t _R4Situation under, expression CH decoder 24 is at t fiducial time _R4Can not set up frame synchronization with interior.In this case, control part 19 distinguishes that CH decoder 24 has fault, and " CH NG " is such shown in Figure 14 (e), shows the unusual information (step S156) of channel Synchronous Processing of CH decoder 24 on display 18.As mentioned above, in this diagnosis algorithm, detect the channel Synchronous Processing when unusual, display 18 is notified the examiner this situation.In view of the above, the examiner can forbid having so unusual receiver Rx to dispatch from the factory.

On the other hand, at step S155, not t _E＞t _R4The time, or when step S154 set up synchronously, control part 19 broke away from from this diagnosis algorithm, entered the step S16 of Fig. 4.Just, control part 19 is moved to the diagnosis algorithm of receiving sensitivity.

1-6. the diagnosis algorithm of receiving sensitivity

As mentioned above, in the qpsk demodulator 21 of Fig. 1, input signal S _IFInput signal S _IFIn comprise carrier power (C) and noise power (N).The ratio of C/N detector 23 detected carrier power (C) and noise power (N), i.e. C/N value.The electric wave receiving sensitivity of this C/N value representation receiver Rx.When this C/N value was not good enough, receiver Rx was not suitable for dispatching from the factory.Therefore, control part 19 is carried out the receiving sensitivity diagnosis algorithm, and whether good, and notify the examiner if detecting receiving sensitivity.

In Fig. 4, control part 19 is judged i _C/NWhether value reaches predetermined value i _Th, just judge whether to satisfy i _C/N〉=i _ThRelation (step S16).Judge just whether the mensuration of C/N value has carried out necessary number of times i _Th

Do not satisfying i _C/N〉=i _ThSituation under, control part 19 is judged as also needs to carry out the C/N pH-value determination pH, breaks away from from this diagnosis is temporary transient.Just control part 19 returns the step S4 of Fig. 2.Therefore, when the examiner carries out key operation and the input of operation keys 17 is arranged, the key that display 18 display operations are crossed (step S4～S6).Thereafter, control part 19 returns step S16 through step S7, S9, S11, S13 and the step S15 of Fig. 3.In the step S15 of this processing procedure, carry out the detection and the i of C/N value _C/NThe increment (the step S151 of Fig. 9 and S152) of value.

On the other hand, satisfying i _C/N〉=i _ThSituation under, necessary number of times has been carried out in the detection of expression C/N value.Therefore, control part 19 is as a step of the diagnosis algorithm of operation keys 17, and (step S17) judged in the input that whether has been taken into whole keys.Control part 19 returns step S4 under the situation of the input that is not taken into whole keys, continues this diagnosis algorithm.Here, although all key all those who are investigated operated, display 18 can demonstrate some keys and not operate sometimes.It is unusual that connector loose contact etc. has taken place such key.By means of this, the examiner just can find that with reference to display 18 operation keys 17 has unusually.For example, shown in Figure 14 (f), although the examiner carried out operation to key " A " sometimes, display 18 does not still show to be operated.In view of the above, the examiner can know that key " A " takes place unusually.As mentioned above, display 18 takes place unusual advisory examiner to operation keys.In view of the above, the examiner can forbid having so unusual receiver to dispatch from the factory.

On the other hand, be taken at step S17 under the situation of whole key inputs, the expression operation keys does not take place unusual, and therefore, control part 19 breaks away from the diagnosis algorithm that returns receiving sensitivity from the diagnosis algorithm of operation keys 17, calculates i _ThThe mean value C/N of individual C/N value _AVE(step S18).Then, judge mean value C/N _AVEWhether than predetermined reference value C/N _Th(step S19) greatly.Fiducial value C/N _ThBe the receiving sensitivity of the judging receiver Rx threshold value of usefulness whether well.If mean value C/N _AVEBe fiducial value C/N _ThBelow, it is big then to comprise noise in the sound of receiver Rx output, thereby this receiver Rx is not suitable for dispatching from the factory.

Not C/N _AVE＞C/N _ThThe time, control part 19 " C/N NG " (" C/N is unusual ") shown in Figure 14 (g) is such, shows the not good enough information (step S20) of receiving sensitivity on display 18.Promptly be judged as receiving sensitivity when not good enough, display 18 is notified the examiner this situation.In view of the above, the examiner can forbid that the not good enough receiver Rx of receiving sensitivity dispatches from the factory.

And in step S19, be judged as C/N _AVE＞C/N _ThThe time, it is good that control part 19 is judged as receiving sensitivity.As a result, control part 19 distinguishes that the receiving sensitivity of operation keys 17, the second stabilized power supply portions 14, PLL circuit 20, qpsk demodulator 21, CH decoder 24 and receiver Rx is all no abnormal.Control part 19 " CHECKOK " (" verification is qualified ") shown in Figure 14 (h) is such, shows receiver Rx diagnostic result good information (step S21) on display 18.In view of the above, the examiner can only allow receiver Rx working properly to dispatch from the factory.

When above factory finished with self diagnostic mode, control part 19 just outputed to the 1st switch 10 to switch control output signal SW, makes this switch conduction.Thus, power source voltage Vcc is offered low frequency amplifier 8, thereby loud speaker 9 exportable sound.So whether normally the examiner can judge receiver Rx output sound by actual listening after the self diagnostic mode that factory uses finishes.Utilize above switch control output signal SW, can carry out finer quality examination.

At last, examiner's operation element mode selector 16 is the routine work pattern with the mode initialization of receiver Rx.The switch A and the B that are about to mode of operation selector 16 are set at conducting (consulting Figure 10).Then, normal receiver Rx is dispatched from the factory, give the user.

2. routine work pattern

The user utilizes receiver Rx music appreciating.At this moment carry out the routine work pattern among the receiver Rx.This pattern is well-known, thereby following routine work mode declaration pattern specification is simplified.At first, the user receives input terminal with not shown antenna.

After the 2nd switch 12 of Fig. 1 is set at conducting, read the switch A of mode of operation selector 16 and the state of B (the step S1 among Fig. 2).Then, control part 19 judges whether will carry out from now on the self diagnostic mode (step S2) that factory uses according to the state that is read.As mentioned above, when dispatching from the factory, the setting state of switch A and B is routine work pattern (consulting Figure 10).Therefore, control part 19 judges whether to carry out maintenance service self diagnostic mode (step S22) from now on.Do not carry out the maintenance service self diagnostic mode owing to current, so execution in step S23.

Described in the prior art part.The broadcasting-satellite service district of " global space " system relates to wide scope.The digital broadcast signal S of fixed statellite broadcasting _DBOccupy different frequency bands in each predetermined area.Therefore, when the user uses this receiver Rx, need to set reception area.At this moment, display 18 shown in Figure 14 (i), demonstrate " SERVICEAREA No.? _ " (" the service area number? _ "), impel the examiner to import the information of identification reception area.And for example described in the prior art part, digital broadcast signal S _DBThe predetermined n road voice data of middle multiple connection.Therefore, when the user appreciates digital broadcasting with this receiver Rx, must inputting channel.Because more than, user's operating operation key 17 is specified reception area and channel.Operation keys 17 produces the signal S of identification reception area _AREASignal S with channel-identification _CH

At step S23, control part 19 is at first obtained the signal S that operation keys 17 produces _AREA Control part 19 utilizes according to signal S _AREAThe frequency control data D that produces _FREQ, the frequency acceptance band of adjustment tuner 2.Thus, tuner 2 beginning receiving digital broadcast signal S _DB

The digital broadcast signal S that fixed statellite is sent _DBAfter receiving by antenna and input terminal 1 by tuner 2, down-convert to intermediate-freuqncy signal S _IFSignal S _IFOutput to qpsk demodulator 21.

Qpsk demodulator 21 is with the signal S of QPSK modulation _IFBe demodulated into baseband signal S _BBAfter, reproduce prime frame β (consulting Figure 19 (b)).The prime frame β that reproduces is outputed to CH decoder 24.

With signal S _AREATogether, control part 19 is also obtained the signal S of channel-identification _CHControl part 19 is according to signal S _CH, produce CH control data D _CHUtilize CH control data D _CH, the audio data frame α that identification CH decoder 24 will be deciphered.

Shown in Figure 19 (b), prime frame β is every time T ₂Repeat to send.Therefore, CH decoder 24 is imported prime frame β successively.At first, CH decoder 24 carries out frame synchronization process, the stem of identification each prime frame β that imports.In case the frame synchronization of foundation is just extracted CH control data D from each prime frame β _CHThe data block of specified channel.After the data block of 24 pairs of extractions of CH decoder rearranges, reproducing audio data frame α.CH decoder 24 from stem, outputs to MPEG decoder 6 with audio data frame α after carrying out the channel Synchronous Processing.

MPEG decoder 6 will in addition after the audio data frame α expansion of digital compression, reproduce original voice data, and output to D/A converter 7 according to MP3.D/A converter 7 outputs to low frequency amplifier 8 with this analog audio data after the digital audio-frequency data of importing is transformed to analog audio data.The analog audio data of 8 pairs of inputs of low frequency amplifier is amplified, and drives loud speaker 9 with the voice data after amplifying.Loud speaker 9 outputs are based on the sound of input audio data.

Utilize above such routine work pattern, the user can appreciate digital broadcasting.Yet receiver Rx breaks down in user's use sometimes.At this moment, receiver Rx is repaired near the maintenance center the user entrusts etc.In this case, the fault place of receiver Rx need be discerned in the maintenance center.For this reason, receiver Rx carries out the self diagnostic mode that the maintenance service that the following describes is used.

3. the self diagnostic mode used of maintenance service

As mentioned above, the self diagnostic mode that factory uses requires high-precision quality examination, thereby uses the analog signal S of signal generator always _SUMYet, the signal generator expensive price, some service center etc. does not often have signal generator.Therefore, receiver Rx uses the digital broadcast signal S of the actual transmission of fixed statellite in oneself checking the maintenance service usefulness self diagnostic mode that fault is used _DBTherefore, maintenance service is different with self diagnostic mode with self diagnostic mode and factory.Below just difference is illustrated, the explanation of two kinds of pattern something in common is omitted.

At first, the examiner of maintenance service execution etc. carries out the preparation of maintenance service with self diagnostic mode for checking fault.The examiner connects input terminal 1 with (not shown) antenna.And then, examiner's operation element mode selector 16 is set, receiver Rx is carried out the self diagnostic mode that maintenance service is used as the pattern of current execution, switch " A " is set at " 0 " (blocking-up), again switch " B " is set at " 1 " (conducting) (with reference to Figure 10).

As mentioned above, digital broadcast signal S _DBOccupy different frequency bands in each area.Therefore, receiver Rx uses digital broadcast signal S _DBThe examiner must import receiving area, the receiver Rx frequency band that will receive just when carrying out the self diagnosis of fault.Again, digital broadcast signal S _DBThe predetermined n road voice data of middle multiple connection.Therefore, the examiner carries out this diagnostic mode in order to make this receiver Rx, must be with a certain channel input.Therefore, examiner's operating operation key 17 is specified reception area (Figure 14 (i)), but also specified channel.Operation keys 17 produces the signal S of identification reception area _AREASignal S with channel-identification _CH

At step S24, control part 19 at first is taken into the signal S that operation keys 17 produces _AREAAnd signal S _CHSignal S _AREAAnd signal S _CHBe stored in the storage area (step S24) of control part 19.Thereafter, control part 19 is carried out above-mentioned steps S3.Also have, at diagnosis algorithm (with reference to the step S109 of Fig. 6) the use signal S of PLL20 _AREA

With in the self diagnostic mode, as mentioned above, use the actual digital broadcast signal S that sends to the coverage in maintenance service _DBTherefore, tuner 2 must be according to the mutually different digital broadcast signal S in location selective reception occupied frequency band zone of service center etc. _DBTherefore, in the diagnosis algorithm of PLL circuit 20 shown in Figure 6, comprise and be used to the step S101 that judges whether maintenance service is being carried out with self diagnostic mode.

At step S101, to carry out with self diagnostic mode in case be judged as maintenance service, control part 19 is just according to the signal S that keeps at step S24 _AREAGenerated frequency control data D _FREQAs mentioned above, current with digital broadcast signal S _DBOffer receiver Rx.Digital broadcast signal S _DBIt is the frequency f of distributing to reception area _C2Carrier wave at the prime frame β of Figure 19 (b) signal through the QPSK modulation.So digital broadcast signal S _DBBe contained in frequency f _C2Occupied frequency band B for centre frequency _C2Control part 19 is sent the frequency control data D of generation _FREQ(step S109) is set in occupied frequency band B with the frequency acceptance band of tuner 2 _C2By means of this, tuner 2 beginning receiving digital broadcast signal S _DB, carry out down-conversion.After step S109, control part 19 enters step S103.

As mentioned above, receiver Rx receives the digital broadcast signal S based on time-division multiplex multiple connection technology and the generation of QPSK modulation technique in normal operation mode _DB, output sound.Receiver Rx carries out two kinds of self diagnostic modes as required.In any self diagnostic mode, whether the control part 19 of receiver Rx is all normally diagnosed the each several part that constitutes this receiver Rx.Just receiver Rx carries out self diagnosis.Alleviate the work load of examiner in the inspection of quality examination or trouble shoot with this.And control part 19 can also utilize self processing procedure, and (whether each determining step among Fig. 2～Fig. 9) is normally judged reliably to each component part.

Two diagnostic modes comprise the diagnosis algorithm of operation keys the 17, the 2nd stabilized power supply portion 14, PLL circuit 20, qpsk demodulator 21, frame synchronization process and receiving sensitivity.Wherein, in the diagnosis algorithm of operation keys 17, operation keys 17 generates the signal corresponding with the key of examiner's practical operation.The signal that control part 19 generates according to operation keys 17, the key of operating display 18 display operation persons.Like this, in the diagnosis algorithm of operation keys 17, because the operation that will ask for help, even control part 19 operate at high speeds also must be waited for people's operation.And the quality of receiving sensitivity is judged according to the C/N value of change in time.For the correct quality of judging receiving sensitivity, require the C/N value is repeatedly measured, and require once to be measured to the time of a certain length of measuring interval subsequently from certain.Therefore, the execution of just connecting of the diagnosis algorithm of supposing operation keys 17 and the diagnosis algorithm of receiving sensitivity, in this case, control part 19 is absorbed in holding state easily in two cover diagnosis algorithms.Neutral was arranged on the time just.From the viewpoint of operating time of shortening the examiner, must reduce the neutral of such time.

Therefore, in this example, utilize the execution of the processing procedure of Fig. 2～Fig. 9, an example as shown in figure 15 is such, carries out each diagnosis algorithm of the 2nd stabilized power supply portion 14, PLL circuit 20, qpsk demodulator 21, frame synchronization process and channel Synchronous Processing in the middle of the diagnosis algorithm of executable operations key 17 or receiving sensitivity.Wherein, Figure 15 represents step (Phase) transition with the situation of self diagnostic mode about factory.That is to say that each diagnosis algorithm of the 2nd stabilized power supply portion 14, PLL circuit 20, qpsk demodulator 21, frame synchronization process and channel Synchronous Processing can utilize the time neutral that takes place at control part 19 to carry out.Whether by means of this, control part 19 can effectively utilize the time, carries out a large amount of diagnosis algorithms, therefore, can diagnose the each several part of formation itself normal at a high speed.That is to say, above-mentioned 2 kinds of self diagnostic modes all need processing time can access shortening.

Again, receiver Rx has the structure that can connect signal generator.With in the self diagnostic mode, use the analog signal S of automatic signal generator in factory _SUMWith this can provide can with the dispatch from the factory corresponding receiver Rx of quality examination in stage of the factory of strict inspection.

And, in the self diagnostic mode that maintenance service is used, the digital broadcast signal S that can use fixed statellite to send out _DBBy means of this, expensive signal generator can not used in maintenance center etc., and is easy and find out fault reliably the place takes place.

Also have, possess under the situation of signal generator in the maintenance center etc.,, also can carry out the self diagnostic mode that factory uses in order to find the fault place.

In the above example, control part 19 judges according to the C/N value whether receiving sensitivity is good.Yet the C/N value is an example of this receiving sensitivity index of expression.As other examples, also available BER (Bit Error Rate: bit error rate).Figure 16 represents to judge according to BER the structure of the receiver Rx of receiving sensitivity.Compare with the receiver of Fig. 1, the receiver difference of Figure 16 just possesses BER detector 29, and no longer is C/N detector 23.Therefore, Figure 10 clearly expresses this difference.

BER detector 29 is arranged between CH decoder 24 and the control part 19.BER detector 29 detects BER according to the result of CH decoder 24 decodings, and sends the BER that measures to control part 19.Has relation shown in Figure 17 between this BER and the C/N value.Therefore, even the BER that obtains notifying is used in control part 19 supposition, also the situation with the C/N value is identical, can judge whether receiving sensitivity is good.

In the above example, display 18 is notified the exception of examiner's receiver Rx.Yet, also be not difficult to make the exception of loud speaker 9 usefulness sound notification receiver Rx.So long as notify the component part (the notice portion in the claim) of the check result of examiner's control part 19, which type of structure division receiver Rx comprises can.

In detailed description of the present invention, above-mentioned explanation is the illustrative explanation to each side of the present invention, but is not limited thereto.The design of its many distortion is also in protection scope of the present invention.

Claims (3)

1. a self-diagnosing method receives the digital broadcast signal that sends out from artificial satellite at ordinary times, and is that the receiver of output sound is carried out as required, diagnose at this receiver itself whether unusual method takes place voluntarily, it is characterized in that,

Time division multiplexing is the audio data frame of the voice data generation of way according to the rules, and constitutes prime frame according to the audio data frame of multiplexing, uses the prime frame that is constituted that carrier wave is carried out the QPSK modulation again, thereby generates digital broadcast signal; This self-diagnosing method comprises:

Diagnosis drives each driving voltage that described receiver uses whether in suitable scope, and the 1st outside diagnosis algorithm of this diagnostic result notice,

To the input signal of described receiver is mixed with local oscillation output, can the PLL circuit that generating the down-conversion of intermediate-freuqncy signal needs correctly be established synchronously and diagnose, and the 2nd diagnosis algorithm of this diagnostic result notice outside,

The intermediate-freuqncy signal that described down-conversion is generated is carried out the QPSK demodulation, reappears the qpsk demodulator that needs in the QPSK demodulation process of prime frame and whether correctly establish and diagnoses synchronously, and the 3rd outside diagnosis algorithm of this diagnostic result notice,

To in the frame synchronization process that detects the stem of utilizing the prime frame that described QPSK demodulation process reproduces, whether correctly detect this stem and diagnose, and the 4th outside diagnosis algorithm of this diagnostic result notice,

To being according to after the reproducing audio data frame with each prime frame of utilizing described frame synchronization process to detect stem, detect in the channel Synchronous Processing of stem of audio data frame of reproduction, whether correctly detect this stem and diagnose, and the 5th outside diagnosis algorithm of this diagnostic result notice,

To the 6th diagnosis algorithm of whether correctly working and diagnosing as the operation keys of user interface, and

Repeated detection is imported the C/N value of the intermediate-freuqncy signal of described qpsk demodulator, calculates the mean value of detected each C/N value, diagnoses the 7th diagnosis algorithm of quality of the receiving sensitivity of described receiver according to the mean value that calculates;

Described the 1st～the 5th diagnosis algorithm utilizes the time of vacating in the described the 6th and the 7th diagnosis algorithm to carry out respectively.

2. self-diagnosing method according to claim 1 is characterized in that described receiver can connect the signal generator of the analog signal that described digital broadcast signal takes place,

Use the input signal of the analog signal of described signal generator generation in described the 2nd diagnosis algorithm as described receiver.

3. self-diagnosing method according to claim 1 is characterized in that, described receiver can connect antenna in order to receive described digital broadcast signal,

In described the 2nd diagnosis algorithm,, use digital broadcast signal by described antenna input as the input signal of receiver.

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