What is carrier lock and bit lock?
I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock", "bit lock" and "bit sync" - what exactly does this mean?
communication communication-satellite radio-communication data-transmission telecommunication
asked 2 hours ago
OZ1SEJ
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I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock", "bit lock" and "bit sync" - what exactly does this mean?
communication communication-satellite radio-communication data-transmission telecommunication
asked 2 hours ago
OZ1SEJ
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock", "bit lock" and "bit sync" - what exactly does this mean?
communication communication-satellite radio-communication data-transmission telecommunication
asked 2 hours ago
OZ1SEJ
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock", "bit lock" and "bit sync" - what exactly does this mean?
communication communication-satellite radio-communication data-transmission telecommunication
communication communication-satellite radio-communication data-transmission telecommunication
asked 2 hours ago
OZ1SEJ
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OZ1SEJ
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OZ1SEJ
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
OZ1SEJ
112
asked 2 hours ago
OZ1SEJ
112
112
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
OZ1SEJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
1 Answer
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First you lock on to energy at (or near) the expected frequency. That’s carrier lock.
Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock.
But those are not yet bits because the coding works in blocks of bits. Once you find the edges of those blocks, you can decode the bits in them: bit lock.
Finally, you work through those bits to figure out which means what in the data stream, synchronizing your view of the bits meaning with the transmitter’s: bit synch.
There’s more on the New Horizons hardware that does this here.
answered 1 hour ago
Bob Jacobsen
4,795625
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
First you lock on to energy at (or near) the expected frequency. That’s carrier lock.
Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock.
But those are not yet bits because the coding works in blocks of bits. Once you find the edges of those blocks, you can decode the bits in them: bit lock.
Finally, you work through those bits to figure out which means what in the data stream, synchronizing your view of the bits meaning with the transmitter’s: bit synch.
There’s more on the New Horizons hardware that does this here.
answered 1 hour ago
Bob Jacobsen
4,795625
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
add a comment |
First you lock on to energy at (or near) the expected frequency. That’s carrier lock.
Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock.
But those are not yet bits because the coding works in blocks of bits. Once you find the edges of those blocks, you can decode the bits in them: bit lock.
Finally, you work through those bits to figure out which means what in the data stream, synchronizing your view of the bits meaning with the transmitter’s: bit synch.
There’s more on the New Horizons hardware that does this here.
answered 1 hour ago
Bob Jacobsen
4,795625
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
add a comment |
First you lock on to energy at (or near) the expected frequency. That’s carrier lock.
Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock.
But those are not yet bits because the coding works in blocks of bits. Once you find the edges of those blocks, you can decode the bits in them: bit lock.
Finally, you work through those bits to figure out which means what in the data stream, synchronizing your view of the bits meaning with the transmitter’s: bit synch.
There’s more on the New Horizons hardware that does this here.
answered 1 hour ago
Bob Jacobsen
4,795625
First you lock on to energy at (or near) the expected frequency. That’s carrier lock.
Then you start to look for patterns in how the phase changes. The transmitter is coding groups of bits as phase-change “symbols”, and you want to find the time-pattern of those: symbol lock.
But those are not yet bits because the coding works in blocks of bits. Once you find the edges of those blocks, you can decode the bits in them: bit lock.
Finally, you work through those bits to figure out which means what in the data stream, synchronizing your view of the bits meaning with the transmitter’s: bit synch.
There’s more on the New Horizons hardware that does this here.
answered 1 hour ago
Bob Jacobsen
4,795625
answered 1 hour ago
Bob Jacobsen
4,795625
answered 1 hour ago
Bob Jacobsen
4,795625
answered 1 hour ago
Bob Jacobsen
4,795625
4,795625
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
add a comment |
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
speaking of bits and blocks, any thoughts on what is or isn't considered "spread-spectrum" Have deep-space spacecraft always used some form of spread-spectrum for data downlink?
– uhoh
28 mins ago
add a comment |
OZ1SEJ is a new contributor. Be nice, and check out our Code of Conduct.
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