JP5251414B2 - Burst optical signal receiving apparatus, burst optical signal processing apparatus, and burst optical signal receiving method - Google Patents

Description

  The present invention relates to a burst optical signal receiving device, a burst optical signal processing device, and a burst optical signal receiving method, and more particularly, to a burst optical signal receiving device connected to a processing device via capacitive means such as a capacitor. The present invention relates to a burst optical signal processing device and a burst optical signal receiving method.

  At present, as one of FTTH (Fiber To The Home) services, a Point to Multi Point service using PON (Passive optical network) is known.

  In the PON system, a continuous signal similar to normal optical communication is used as a downlink signal transmitted from a local device OLT (Optical Line Terminal) to a subscriber device ONU (Optical Network Unit).

  On the other hand, a time division multiple access (TDMA) system is adopted for the uplink signal transmitted from the subscriber unit ONU to the local device OLT. Therefore, an optical signal obtained by time-division multiplexing burst-like packet signals transmitted individually for each user, that is, an intermittent burst optical signal is used as the upstream signal.

  For this reason, the local device OLT is required to receive intermittent burst optical signals.

  In the local device OLT, a burst optical signal receiving device receives a burst optical signal, converts the burst optical signal into a burst signal of an electrical signal, and a logic LSI (Large LSI) including a PON MAC (Media Access Control) in the subsequent stage. Scale Integration), that is, the processing unit performs logic processing on the burst signal.

  The main part of the burst optical signal receiving apparatus is an analog circuit. For example, when high-speed communication of 10 Gbps class or higher is performed, a CML (Current Mode Logic) circuit is used as a basic circuit of an analog circuit.

  On the other hand, the main part of the logic LSI (processing device) is realized by a complementary metal oxide semiconductor (CMOS) circuit.

  In recent years, with the progress of miniaturization process technology, high integration and high speed of LSI composed of CMOS circuits have been realized. With miniaturization, the withstand voltage of the transistor decreases. For this reason, the power supply voltage of an LSI constituted by a CMOS circuit has changed from 3.3 V to 2.5 V and 1.8 V, and has recently become 1.3 V. This trend is expected to continue. There is also a merit that power consumption is reduced due to a drop in power supply voltage.

  On the other hand, unlike the CMOS logic circuit, the analog circuit does not decrease the power supply voltage due to miniaturization.

  For this reason, when transferring burst signals, which are electrical signals, between burst optical signal receivers and logic LSIs (processing devices), the power supply voltages of the two are different, so burst signal transfer is not DC coupled. Must be realized with AC coupling.

  In the AC coupling, a capacitive element such as a capacitor is used, so that a high pass filter circuit (hereinafter referred to as “HPF”) having the capacitive element as a constituent element is formed.

  This HPF causes the following problems regarding the delivery of burst signals.

  Usually, since the ratio of “1” and “0” of the transmission signal is averaged, the average mark ratio is 0.5.

  A burst optical signal receiving apparatus receives a burst optical signal corresponding to a packet with an average mark ratio of 0.5 and a guard time (no signal) following the burst optical signal, and an electric signal corresponding to the burst signal and the guard time If signals, that is, no signals are output in order, a DC level drift depending on the time constant of the HPF occurs with the generation of no signals according to the guard time.

  Due to this DC level drift, the beginning of the next packet (the beginning of the burst signal) is affected in the same way as the decrease in signal amplitude.

  It takes time depending on the time constant of HPF until this effect is mitigated.

  For this reason, the logic LSI (processing device) cannot receive the burst signal accurately for this time, and there is a problem that the transmission efficiency is lowered.

  The DC level drift depending on the HPF time constant and the decrease in the signal amplitude at the beginning of the next packet will be described below with reference to FIGS.

  FIG. 9 is an explanatory view showing a burst optical signal processing device of related art.

  In FIG. 9, the output signal from the burst optical signal receiving apparatus 1000 is provided to a processing circuit 1170 such as a logic LSI through a capacitor 1160 by AC coupling. The HPF is formed by the capacitor 1160 and the termination resistor 1170a in the processing circuit 1170.

  The burst optical signal receiving apparatus 1000 includes an APD (Avalanche Photo Diode) 1110 that is a photoelectric conversion unit, and a TIA / LA 1120 that is an amplifier circuit. “TIA” means Trans Impedance Amplifier, and “LA” means Limiter Amplifier.

  FIG. 10 is a timing chart for explaining the operation of the related art burst optical signal processing apparatus.

  In FIG. 10A, a waveform 1101 is a waveform of an optical signal input to the APD 1110, and is also a waveform of an output signal (electric signal) from the TIA / LA 1120. The waveform 1101 includes a burst optical signal (burst signal) 1101a and a guard time (no signal) 1101b.

  A waveform 1101c is a waveform indicating an average voltage associated with the waveform 1101. As shown in the waveform 1101c, when a guard time (no signal) 1101b occurs, the average voltage changes according to the time constant of the HPF.

  In FIG. 10B, a waveform 1161 is a waveform that has passed through the HPF.

  As shown in the waveform 1161, with the generation of the electrical signal corresponding to the guard time (no signal) 1101b, a DC level drift occurs depending on the time constant of the HPF, and the signal amplitude is detected at the beginning of the next packet. Affected by the same decrease.

  The relaxation time can be shortened by shortening the HPF time constant.

  However, shortening the time constant of the HPF is equivalent to simultaneously limiting the same sign continuous bit tolerance of the transmission signal. That is, there is a problem that it is impossible to achieve both the shortening of the relaxation time and the continuous strength of the same sign.

  Patent Documents 1 and 2 describe a technique that can solve the problem of reduced transmission efficiency due to HPF.

  Patent Document 1 describes a burst optical signal receiver that inserts a dummy optical pulse train between burst optical signals and burst optical signals, that is, at a guard time (no signal).

Patent Document 2 describes a burst signal light receiving apparatus that injects an optical clock signal between burst optical signals, that is, at a guard time (no signal).
JP 2006-304070 A JP 2004-222116 A

  According to the technique described in Patent Document 1 and the technique described in Patent Document 2, it is possible to suppress a decrease in the reception efficiency of burst optical signals.

  However, in the technique described in Patent Document 1 and the technique described in Patent Document 2, an optical signal different from the burst optical signal (a dummy optical pulse in the technique described in Patent Document 1 and an optical clock signal in the technique described in Patent Document 2). ) Is generated, and the burst optical signal receiver receives the burst optical signal and an optical signal different from the burst optical signal.

  For this reason, there is a problem that an optical signal that is more difficult to handle than an electrical signal is newly generated, and the newly generated optical signal must be processed in addition to the burst optical signal.

  Therefore, for example, the cost associated with the generation of the optical signal increases. Further, since the burst optical signal receiving apparatus receives a burst optical signal and an optical signal different from the burst optical signal, the burst optical signal receiving apparatus receives the optical signal via the optical communication line. For this reason, optical loss occurs when the optical signal passes through the optical communication line.

  An object of the present invention is to provide a burst optical signal receiving device, a burst optical signal processing device, and a burst optical signal receiving method capable of solving the above-described problems.

  The burst optical signal receiving apparatus of the present invention is a burst optical signal receiving apparatus connected to a processing device through a capacity means, and receives the burst optical signal and converts the burst optical signal into an electrical burst signal. And converting means for outputting, generating means for generating a pulse signal of an electric signal, and when the burst signal is output, providing the burst signal to the processing device via the capacity means, Providing means for providing the pulse signal to the processing device via the capacity means when a burst signal is not output.

  The burst optical signal processing device of the present invention receives the burst signal and the pulse signal from the burst optical signal receiving device via the burst optical signal receiving device, the capacity means, and the capacity means, And a processing device for extracting and processing the signal.

  The burst optical signal processing device of the present invention is a burst optical signal processing device including a burst optical signal receiving device, a capacity unit, and a processing device connected to the burst optical signal receiving device via the capacity unit. The burst optical signal receiving device receives the burst optical signal, converts the burst optical signal into a burst signal of an electrical signal, outputs the burst optical signal, a generation unit that generates a pulse signal of the electrical signal, and the burst Superimposing means that superimposes the pulse signal on a signal to generate a superimposed signal and provides the superimposed signal to the processing device via the capacitance means, the processing device including the burst from the superimposed signal Extraction means for extracting the signal is included.

  The burst optical signal receiving method of the present invention is a burst optical signal receiving method performed by a burst optical signal receiving device connected to a processing device via a capacity means. When receiving the burst optical signal, the burst optical signal is electrically converted. A conversion step of converting the signal into a burst signal and outputting; a generation step of generating a pulse signal of an electrical signal; and if the burst signal is output, the burst signal is transmitted through the capacitor means. Providing to a processing device, and providing the pulse signal to the processing device via the capacitive means when the burst signal is not output.

  The burst optical signal receiving method of the present invention is a burst performed by a burst optical signal processing apparatus including a burst optical signal receiving apparatus, capacity means, and a processing apparatus connected to the burst optical signal receiving apparatus via the capacity means. An optical signal receiving method, wherein the burst optical signal receiving device receives a burst optical signal, converts the burst optical signal into a burst signal of an electrical signal, and outputs the burst optical signal, and the burst optical signal receiving device A generation step of generating a pulse signal of an electrical signal, and the burst optical signal receiving device generates a superimposed signal by superimposing the pulse signal on the burst signal, and the superimposed signal is generated through the capacitor means. A superimposing step provided to a processing device; and an extracting step in which the processing device extracts the burst signal from the superposed signal.

  According to the present invention, it is possible to suppress a decrease in the reception efficiency of a burst optical signal without generating and processing a new optical signal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a burst optical signal processing apparatus according to a first embodiment of the present invention.

  In FIG. 1, the burst optical signal processing apparatus 1 includes a burst optical receiver 100, a capacitor 160, and a logic circuit 170.

  Burst optical receiver 100 can be generally referred to as a burst optical signal receiver. Capacitor 160 can generally be referred to as a capacitive means. Logic circuit 170 can generally be referred to as a processing device. The burst optical receiver 100 is connected to the logic circuit 170 via the capacitor 160.

  The burst optical receiver 100 includes a photoelectric conversion unit (hereinafter referred to as “APD”) 110, an amplifier circuit (hereinafter referred to as “TIA / LA”) 120, a dummy signal oscillation circuit (hereinafter simply referred to as “oscillation circuit”). 130), a selector 140, and a packet detection circuit 150.

  “APD” means Avalanche Photo Diode, “TIA” means Trans Impedance Amplifier, and “LA” means Limiter Amplifier. .

  The APD 110 and the TIA / LA 120 are included in the conversion unit 100a. The selector 140 and the packet detection circuit 150 are included in the providing unit 100b.

  Conversion unit 100a can be generally referred to as conversion means.

  When receiving the burst optical signal, the converter 100a converts the burst optical signal into a burst signal of an electrical signal and outputs the burst signal. In the present embodiment, the burst optical signal is an optical signal corresponding to a packet.

  When the APD 110 receives the burst optical signal, the APD 110 converts the burst optical signal into a burst signal of an electrical signal and outputs it to the TIA / LA 120.

  When TIA / LA 120 receives a burst signal, TIA / LA 120 amplifies the burst signal and outputs the amplified burst signal (that is, burst signal).

  Oscillation circuit 130 can generally be referred to as generating means.

  The oscillation circuit 130 generates a pulse signal of electric signal (hereinafter referred to as “dummy signal”). The oscillation circuit 130 generates a signal having a frequency that passes through a filter (HPF) configured by the capacitor 160 and the termination resistor 170a in the logic circuit 170 as a dummy signal.

  In the present embodiment, the oscillation frequency of the oscillation circuit 130 is higher (for example, sufficiently high) than the low-frequency cutoff of the filter (HPF) configured by the capacitor 160 and the termination resistor 170a.

  Providing unit 100b can be generally referred to as providing means.

  When the burst signal is output from the conversion unit 100a, the providing unit 100b provides the burst signal to the logic circuit 170 by AC coupling using the capacitor 160.

  On the other hand, when the burst signal is not output from the conversion unit 100a, the providing unit 100b provides the dummy signal from the oscillation circuit 130 to the logic circuit 170 by AC coupling using the capacitor 160.

  Packet detection circuit 150 can be generally referred to as determination means.

  The packet detection circuit 150 determines whether a burst signal is output from the conversion unit 100a based on the output signal from the TIA / LA 120. The packet detection circuit 150 provides the determination result to the selector 140. In the present embodiment, the packet detection circuit 150 also provides the determination result to the logic circuit 170.

  FIG. 2 is a block diagram illustrating an example of the packet detection circuit 150.

  In FIG. 2, the packet detection circuit 150 includes a peak detection circuit 151 and a comparator 152.

  The peak detection circuit 151 detects the peak of the output signal from the TIA / LA 120 and outputs the detection result to the comparator 152.

  The comparator 152 compares the detection result of the peak detection circuit 151 with the reference voltage (Ref.).

  When the detection result of the peak detection circuit 151 is equal to or higher than the reference voltage, the comparator 152 outputs “1” as the determination result. On the other hand, when the detection result of the peak detection circuit 151 is less than the reference voltage, the comparator 152 outputs “0” as the determination result.

  Therefore, the peak detection circuit 151 outputs “1” as a determination result when the conversion unit 100a outputs a burst signal, that is, when the conversion unit 100a receives a burst optical signal corresponding to a packet. . On the other hand, when the conversion unit 100a does not output the burst signal, that is, when the conversion unit 100a does not receive the burst optical signal corresponding to the packet, “0” is output as the determination result.

  Returning to FIG. 1, selector 140 can be generally referred to as switching means.

  Based on the determination result from the packet detection circuit 150, the selector 140 switches the signal output to the logic circuit 170 between the burst signal and the dummy signal.

  In the present embodiment, when the determination result indicates that the burst signal is output, that is, when the determination result is “1”, the selector 140 converts the burst signal into a logic circuit by AC coupling via the capacitor 160. 170.

  On the other hand, when the determination result indicates that the burst signal is not output, that is, when the determination result is “0”, the selector 140 provides the dummy signal to the logic circuit 170 through the capacitor 160 by AC coupling. To do.

  When the logic circuit 170 receives the output signal of the selector 140 via the capacitor 160, the logic circuit 170 extracts a burst signal from the output signal and performs logic processing on the burst signal.

  The logic circuit 170 includes a reception circuit 170b and a processing circuit 170c.

  The reception circuit 170b includes a termination resistor 170a and receives an output signal of the selector 140 via the capacitor 160. The reception circuit 170b outputs the output signal of the selector 140 to the processing circuit 170c.

  When the processing circuit 170c receives the output signal of the selector 140 via the reception circuit 170b, the processing circuit 170c detects a burst signal from the output signal and performs logical processing on the burst signal.

  The processing circuit 170 c detects a burst signal from the output signal of the selector 140 using the determination result from the packet detection circuit 150.

  In this embodiment, the processing circuit 170c detects the output signal of the selector 140 as a burst signal when the determination result is “1”, and deletes the output signal of the selector 140 when the determination result is “0”. The output signal of the selector 140 is set to a no signal state.

  Next, the operation will be described.

  3A to 3C are timing charts for explaining the operation of the burst optical receiver 100. FIG. The operation of the burst optical receiver 100 will be described below with reference to FIGS. 3 (a) to 3 (c).

  In FIG. 3A, a waveform 301 is a waveform of an optical signal input to the APD 110, and is also a waveform of an output signal (electric signal) from the TIA / LA 120. The waveform 301 includes a burst optical signal (burst signal) 301a and a guard time (no signal) 301b. In FIG. 3B, a waveform 302 is an output waveform (determination result) of the packet detection circuit 150. In FIG. 3C, a waveform 303 is an input waveform to the logic circuit 170.

  As shown in the waveform 301, in the no-signal state between the burst signal and the next burst signal, the average voltage value of the output signal of the TIA / LA 120 decreases. Further, as shown by the waveform 302, in the no signal state, the output of the packet detection circuit 150 is “0” which means a no packet signal.

  Upon receiving “0” from the packet detection circuit 150, the selector 140 switches the signal provided to the logic circuit 170 via the capacitor 160 from the signal from the TIA / LA 120 to the signal from the oscillation circuit 130.

  The determination result of the packet detection circuit 150 is also input to the logic circuit 170.

  Therefore, the logic circuit 170 can determine whether the signal received via the capacitor 160 is a burst signal or a dummy signal in a no-signal state by referring to the determination result.

  On the other hand, when the no-signal state ends and a burst signal is input, the output waveform 302 of the packet detection circuit 150 becomes “1”.

  Upon receiving “1” from the packet detection circuit 150, the selector 140 switches the signal provided to the logic circuit 170 via the capacitor 160 from the signal from the oscillation circuit 130 to the signal from the TIA / LA 120.

  The oscillation frequency of the oscillation circuit 130 is higher (for example, sufficiently high) than the low-frequency cutoff of the HPF configured by the capacitor 160 and the termination resistor 170a. Therefore, even if the output signal of the selector 140 is provided to the logic circuit 170 by AC coupling, the average voltage fluctuates so as to affect reception at the subsequent stage (in this embodiment, the logic circuit 170). Therefore, a stable reception operation can be performed.

  Next, the effect of this embodiment will be described.

  According to the present embodiment, in a burst optical signal receiving apparatus having AC coupling, it is possible to realize accurate signal reception without depending on the relaxation time by the AC coupling HPF. For this reason, it is possible to effectively utilize a low-cost burst optical signal receiving apparatus that does not lower the transmission efficiency and does not sacrifice the same sign continuous bit tolerance of the transmission signal.

  By applying AC coupling, it becomes possible to connect circuits having different power supply voltages, and to transmit signals between the circuits.

  Further, by using the present embodiment for the local device OLT of the PON system, it is possible to realize the local device OLT that receives an upstream signal of an efficient 10 Gbps class PON system.

  According to the present embodiment, the providing unit 100b provides the burst signal to the logic circuit 170 via the capacitor 160 when the burst signal of the electrical signal converted from the burst optical signal is output. When no signal is output, the dummy signal (pulse signal) generated by the oscillation circuit 130 is provided to the logic circuit 170 via the capacitor 160.

  For this reason, a dummy signal (pulse signal) required during a no-signal state is generated not by an optical signal but by an electrical signal, and a burst signal of the electrical signal and a dummy signal of the electrical signal are alternatively output. .

  Therefore, it is possible to suppress a decrease in the reception efficiency of the burst optical signal without generating and processing a new optical signal.

  In the present embodiment, the oscillation circuit 130 generates a signal having a frequency that passes through a filter composed of the capacitor 160 and the termination resistor 170a in the logic circuit 170 as a dummy signal (pulse signal).

  For this reason, it is possible to reduce the fluctuation of the average voltage of the output signal of the selector 140 by the dummy signal. Therefore, it is possible to suppress a decrease in transmission efficiency due to the fluctuation of the average voltage.

  In the present embodiment, an oscillation circuit 130 that is an oscillator is used as the generation unit. In this case, it is possible to use a simple configuration generating means.

  In the present embodiment, the packet detection circuit 150 provides the determination result to the logic circuit 170. In this case, the logic circuit 170 can detect a burst signal using the determination result.

(Second Embodiment)
FIG. 4 is a block diagram showing a burst optical signal processing apparatus according to the second embodiment of the present invention. In FIG. 4, the same components as those shown in FIG.

  In the burst optical signal processing device 1A shown in FIG. 4, the oscillation circuit 130 shown in FIG. 1 is replaced with a pseudo random pattern generation circuit 131.

  FIG. 5 is a block diagram illustrating an example of the pseudo random pattern generation circuit 131.

  The minimum frequency of the pseudo random signal from the pseudo random pattern generation circuit 131 is higher (for example, sufficiently high) than the low frequency cutoff of the HPF configured by the capacitor 160 and the termination resistor 170a. For this reason, also in this embodiment, the same operation and effect as the first embodiment can be realized.

(Third embodiment)
FIG. 6 is a block diagram showing a burst optical signal processing apparatus according to the third embodiment of the present invention. In FIG. 6, the same components as those shown in FIG.

  In FIG. 6, burst optical signal processing apparatus 1B includes burst optical receiver 200, capacitors 160 and 160B, and logic circuit 270.

  Burst optical receiver 200 can be generally referred to as a burst optical signal receiver. Capacitors 160 and 160B can generally be referred to as capacitive means. Logic circuit 270 can be generally referred to as a processing device. The burst optical receiver 200 is connected to the logic circuit 270 via capacitors 160 and 160B.

  The burst optical receiver 200 includes an APD 110, a TIA / LA 120, a dummy signal generation circuit 132, and an exclusive OR circuit 240.

  Dummy signal generation circuit 132 can be generally referred to as generation means.

  The dummy signal generation circuit 132 generates a pulse signal of an electrical signal (hereinafter referred to as “dummy signal”). The dummy signal generation circuit 132 generates a signal having a frequency that passes through a filter (HPF) configured by the capacitor 160 and the termination resistor 170a in the logic circuit 270 as a dummy signal.

  In the present embodiment, the oscillation frequency of the dummy signal generation circuit 132 is higher (e.g., sufficiently high) than the low-frequency cutoff of the filter (HPF) configured by the capacitor 160 and the termination resistor 170a.

  The exclusive OR circuit 240 can be generally referred to as superimposing means.

  The exclusive OR circuit 240 generates a superimposed signal by superimposing the dummy signal from the dummy signal generation circuit 132 on the burst signal, and provides the superimposed signal to the logic circuit 270 via the capacitor 160 by AC coupling.

  In the present embodiment, the exclusive OR circuit 240 calculates an exclusive OR of the burst signal and the dummy signal from the dummy signal generation circuit 132, and the result of the calculation is output as a superimposed signal via the capacitor 160. Provided to logic circuit 270 by AC coupling.

  The dummy signal generation circuit 132 provides the dummy signal to the logic circuit 270 via the capacitor 160B.

  The logic circuit 270 includes an exclusive OR circuit 241, a reception circuit 170b, and a processing circuit 170c.

  The exclusive OR circuit 241 can be generally referred to as extraction means.

  The exclusive OR circuit 241 extracts a burst signal from the superimposed signal received via the capacitor 160. For example, the exclusive OR circuit 241 extracts a burst signal from the superimposed signal using the dummy signal received via the capacitor 160B.

  In the present embodiment, the exclusive OR circuit 241 calculates an exclusive OR of the superimposed signal and the dummy signal, and extracts a burst signal from the superimposed signal. That is, this calculation result represents a burst signal.

  Next, the operation will be described.

  FIGS. 7A to 7C are timing charts for explaining the operation of the burst optical signal processing apparatus 1B. The operation of the burst optical signal processing apparatus 1B will be described below with reference to FIGS. 7 (a) to 7 (c).

  In FIG. 7A, a waveform 701 is the same as the waveform 301 shown in FIG. In FIG. 7B, a waveform 702 is an output waveform of the exclusive OR circuit 240. In FIG. 7C, a waveform 703 is an output waveform of the exclusive OR circuit 241.

  The exclusive OR circuit 240 calculates the exclusive OR of the signal from the conversion unit 100a (see waveform 701) and the dummy signal from the dummy signal generation circuit 132, and the calculation result (see waveform 702). , And provided to the logic circuit 270 via the capacitor 160.

  In the logic circuit 270, the exclusive OR circuit 241 receives the signal from the burst optical receiver 200 and the output signal from the dummy signal generation circuit 132 by AC coupling, and performs exclusive OR of both signals. Calculate. The calculation result (waveform 703), that is, the burst signal is provided to the reception circuit 170b, and then logical processing is performed in the processing circuit 170c.

  Here, the delay of the path from the dummy signal generation circuit 132 to the exclusive OR circuit 241 via the exclusive OR circuit 240 and the capacitor 160, and the exclusion from the dummy signal generation circuit 132 via the capacitor 160B. The delay of the path to the logical OR circuit 241 must be the same.

  According to the present embodiment, the exclusive OR circuit 240 generates a superimposed signal by superimposing a dummy signal on the burst signal, and provides the superimposed signal to the logic circuit 270 via the capacitor 160. The exclusive OR circuit 241 extracts a burst signal from the superimposed signal.

  In this case, a dummy signal (pulse signal) required in the no-signal state period is generated as an electric signal instead of an optical signal. During the no-signal state, the electric signal dummy signal is logically transmitted via the capacitor 160. Provided to circuit 270.

  Therefore, it is possible to suppress a decrease in the reception efficiency of the burst optical signal without generating and processing a new optical signal.

  In this embodiment, the dummy signal generation circuit 132 provides a dummy signal to the logic circuit 270, and the exclusive OR circuit 241 uses the dummy signal from the dummy signal generation circuit 132 to extract a burst signal from the superimposed signal. To do.

  In this case, it is possible to superimpose and extract signals using the dummy signal from the dummy signal generation circuit 132.

  In this embodiment, the exclusive OR circuit 240 calculates the exclusive OR of the burst signal and the dummy signal, and provides the result of the calculation to the logic circuit 270 via the capacitor 160 as a superimposed signal. The exclusive OR circuit 241 calculates an exclusive OR of the superimposed signal and the dummy signal and extracts a burst signal from the superimposed signal.

  In this case, it is possible to superimpose and extract signals using an exclusive OR circuit.

(Fourth embodiment)
FIG. 8 is a block diagram showing a burst optical signal processing apparatus according to the fourth embodiment of the present invention. In FIG. 8, the same components as those shown in FIG. 6 are denoted by the same reference numerals.

  In the burst optical signal processing device 1C shown in FIG. 8, the logic circuit 270 includes a dummy signal generation circuit 133. By inputting a reset signal (Sync.) To the dummy signal generation circuits 132 and 133 at the same time. Synchronize both circuits.

  Dummy signal generation circuit 133 can be generally referred to as extraction signal generation means.

  The dummy signal generation circuit 133 generates a dummy signal (extraction signal) having the same waveform as the dummy signal from the dummy signal generation circuit 132 and synchronized with the dummy signal.

  The exclusive OR circuit 241 uses the dummy signal from the dummy signal generation circuit 133 to extract a burst signal from the superimposed signal.

  In the present embodiment, the exclusive OR circuit 241 calculates an exclusive OR of the superimposed signal and the dummy signal from the dummy signal generation circuit 133, and extracts a burst signal from the superimposed signal.

  In the present embodiment, similarly to the third embodiment, it is possible to suppress a decrease in the reception efficiency of the burst optical signal without performing generation and processing of a new optical signal, and an exclusive OR circuit is provided. It is possible to superimpose and extract signals.

  Further, according to the present embodiment, in the third embodiment, a delay of a path from the dummy signal generation circuit 132 to the exclusive OR circuit 241 via the exclusive OR circuit 240 and the capacitor 160, and the dummy signal The delay of the path from the generation circuit 132 to the exclusive OR circuit 241 via the capacitor 160B needs to be the same, whereas in this embodiment, such a delay design is unnecessary. There is.

  Each of the above embodiments can be applied to a network system using an optical switch, and in particular, can be applied to an optical access system using time division multiple access (TDMA).

  Further, each of the above embodiments can be applied to a burst optical transmitter and an optical receiver of a PON system. Furthermore, it is applicable to an optical packet switch system and an optical burst communication system in general.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

1 is a block diagram illustrating a burst optical signal processing device according to a first embodiment of the present invention. 3 is a block diagram showing an example of a packet detection circuit 150. FIG. 4 is a timing chart for explaining the operation of the burst optical receiver 100. It is the block diagram which showed the burst optical signal processing apparatus of 2nd Embodiment of this invention. 3 is a block diagram showing an example of a pseudo random pattern generation circuit 131. FIG. It is the block diagram which showed the burst optical signal processing apparatus of 3rd Embodiment of this invention. It is a timing chart for demonstrating operation | movement of the burst optical signal processing apparatus 1B. It is the block diagram which showed the burst optical signal processing apparatus of 4th Embodiment of this invention. It is explanatory drawing which showed the burst optical signal processing apparatus of related technology. It is a timing chart for demonstrating operation | movement of the burst optical signal processing apparatus of related technology.

Explanation of symbols

1, 1A, 1B, 1C Burst optical signal processing device 100, 200 Burst optical receiver 100a Conversion unit 100b Providing unit 110 APD
120 TIA / LA
130 Dummy signal oscillation circuit 131 Pseudo random pattern generation circuit 132, 133 Dummy signal generation circuit 131-1, 131-2, 131-3, 131-4, 131-5, 131-6, 131-7 D-type F / F
131-10 exclusive OR circuit 140 selector 150 packet detection circuit 151 peak detection circuit 152 comparator 160, 160A capacitor 170, 270 logic circuit 170a termination resistor 170b reception circuit 170c processing circuit 240 241 exclusive OR circuit

Claims (11)

A burst optical signal receiving device connected to a processing device via a capacity means,
When receiving the burst optical signal, conversion means for converting the burst optical signal into a burst signal of an electrical signal and outputting it,
Generating means for generating a pulse signal of the electrical signal;
When the burst signal is output, the burst signal is provided to the processing device via the capacity unit, and when the burst signal is not output, the pulse signal is supplied to the capacity unit. see containing and a providing means for providing to the processor via,
The burst optical signal receiving device , wherein the generating unit generates a signal having a frequency that passes through a filter including the capacitor unit and a resistor in the processing device as the pulse signal . The burst optical signal receiving device according to claim 1 ,
The burst optical signal receiving apparatus, wherein the generating means is an oscillator. The burst optical signal receiver according to claim 1 or 2 ,
The providing means includes:
Determining means for determining whether or not the burst signal is output;
When the determination result of the determination unit indicates that the burst signal is output, the burst signal is provided to the processing device via the capacity unit, and the determination result of the determination unit is Switching means for providing the pulse signal to the processing device via the capacity means when indicating that a burst signal is not output,
The burst optical signal receiving apparatus, wherein the determination unit provides the determination result to the processing apparatus. A burst optical signal receiving device according to any one of claims 1 to 3 ,
Capacity means;
A burst optical signal processing device including: a processing device that receives the burst signal and the pulse signal from the burst optical signal receiving device via the capacity unit, and extracts and processes the burst signal; A burst optical signal processing device comprising: a burst optical signal receiving device; a capacity unit; and a processing device connected to the burst optical signal receiving device via the capacity unit,
The burst optical signal receiving device,
When receiving a burst optical signal, the burst optical signal is converted into a burst signal of an electrical signal and output, and when the burst optical signal is not received, conversion means that outputs no signal ,
Generating means for generating a pulse signal of the electrical signal;
Superimposing means for generating a superposition signal by superimposing the pulse signal on the output of the conversion means, and providing the superposition signal to the processing device via the capacitance means,
The processing unit, an extraction means for extracting the burst signal from the superimposed signal, seen including,
The burst optical signal processing apparatus , wherein the generation means generates a signal having a frequency that passes through a filter constituted by the capacitance means and a resistor in the processing apparatus as the pulse signal . In the burst optical signal processing device according to claim 5 ,
The generating means provides the pulse signal to the processing device,
The burst optical signal processing apparatus, wherein the extraction unit extracts the burst signal from the superimposed signal using the pulse signal provided from the generation unit. In the burst optical signal processing device according to claim 5 ,
The processing device further includes extraction signal generation means for generating an extraction signal having the same waveform as the pulse signal and synchronized with the pulse signal,
The burst optical signal processing apparatus, wherein the extraction means extracts the burst signal from the superimposed signal using the extraction signal. The burst optical signal processing device according to claim 6 ,
The superimposing means calculates an exclusive logical sum of the output of the converting means and the pulse signal, and provides the result of the calculation as the superposed signal to the processing device via the capacitive means. Sum circuit,
The burst optical signal processing device, wherein the extraction means is an exclusive OR circuit that calculates an exclusive OR of the superposed signal and the pulse signal and extracts the burst signal from the superposed signal. The burst optical signal processing device according to claim 7 ,
The superimposing means calculates an exclusive logical sum of the output of the converting means and the pulse signal, and provides the result of the calculation as the superposed signal to the processing device via the capacitive means. Sum circuit,
The burst optical signal processing device, wherein the extraction unit is an exclusive OR circuit that calculates an exclusive OR of the superimposition signal and the extraction signal and extracts the burst signal from the superposition signal. A burst optical signal receiving method performed by a burst optical signal receiving device connected to a processing device via a capacity means,
When receiving a burst optical signal, a conversion step for converting the burst optical signal into a burst signal of an electrical signal and outputting the signal,
A generating step for generating a pulse signal of the electrical signal;
When the burst signal is output, the burst signal is provided to the processing device via the capacity unit, and when the burst signal is not output, the pulse signal is supplied to the capacity unit. see containing and a providing step of providing to said processor via a
In the generating step, a burst optical signal receiving method, wherein a signal having a frequency passing through a filter composed of the capacitance means and a resistor in the processing device is generated as the pulse signal . A burst optical signal receiving method performed by a burst optical signal processing device including a burst optical signal receiving device, a capacity unit, and a processing device connected to the burst optical signal reception device via the capacity unit,
When the burst optical signal receiving device receives the burst optical signal, it converts the burst optical signal into a burst signal of an electrical signal and outputs it. When the burst optical signal is not received, the output is no signal. And a conversion step
The burst optical signal receiving device generates an electrical signal pulse signal; and
The burst optical signal receiving device generates a superimposed signal by superimposing the pulse signal on the output in the conversion step, and provides the superimposed signal to the processing device via the capacitance means;
The processing device, viewed contains an extraction step, the extracting the burst signal from the superimposed signal,
In the generating step, a burst optical signal receiving method, wherein a signal having a frequency passing through a filter composed of the capacitance means and a resistor in the processing device is generated as the pulse signal .

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