Cyclical obstruction communication system
Techniques for improving data rates at mobile terminals that are subject to periodic channel interruptions in a beyond-line-of-sight communication system are disclosed, including improved encoding and decoding systems that identify blockages and modify receiver operation during blockages to reduce data errors. In certain embodiments, encoding, symbol mapping, interleaving, and use of unique periodic identifiers function to enable a series of packets that may be received in a blockage impaired channel with reduced errors.
1. A method, comprising;
encoding a series of packets destined for a remote terminal;
interleaving the series of packets, wherein interleaving the series of packets comprises modifying the series of packets to disperse data corrupted from a first size to a second size based on an intermittent obstruction of a wireless channel, and wherein the first size is associated with contiguous data and the second size is smaller than the first size;
inserting periodic unique identifiers within the series of packets following the interleaving of the series of packets, such that each unique identifier of the periodic unique identifiers is associated with a respective portion of the series of packets; and
modulating and transmitting the series of packets including the periodic unique identifiers over the wireless channel.
2. The method of claim 1 , further comprising:
receiving a series of packets including periodic unique identifiers at the remote terminal, wherein the received series of packets are associated with the transmitted series of packets, and wherein the received periodic unique identifiers are associated with the transmitted periodic unique identifiers;
correlating the received periodic unique identifiers with a copy of the transmitted periodic unique identifiers stored at the remote terminal;
determining that the correlation is below a predetermined threshold for a subset of the received periodic unique identifiers;
removing the received periodic unique identifiers from the received series of packets; and
modifying operation of the remote terminal for a portion of the received series of packets associated with the subset of the received periodic unique identifiers.
3. The method of claim 1 , wherein interleaving the series of packets further comprises:
delaying the series of packets by an amount based on a value stored in a register.
4. The method of claim 1 , further comprising:
receiving the series of packets including the periodic unique identifiers at the remote terminal;
modifying operation of the remote terminal for a portion of the received series of packets associated with a subset of the received periodic unique identifiers; and
deinterleaving the received series of packets following the modifying the operation of the remote terminal.
5. The method of claim 4 , wherein deinterleaving the received series of packets further comprises:
modifying the received series of packets to disperse data corrupted from the first size to the second size based on the intermittent obstruction of the wireless channel.
6. The method of claim 5 , wherein deinterleaving the received series of packets further comprises:
delaying the received series of packets by an amount based on a value stored in a register.
7. The method of claim 6 , wherein the amount is based on a second amount associated with interleaving the series of packets.
8. A remote terminal including a receiver, the receiver comprising:
a demodulator that receives a series of packets including periodic unique identifiers at the remote terminal via a blockage impaired channel;
a correlation data remover, wherein the correlation data remover creates a signal blockage indicator based on the received periodic unique identifiers and a threshold; and
a deinterleaver that implements a de-interleaving process on the received series of packets following the creation of the signal blockage indicator, wherein to implement the de-interleaving process the deinterleaver is further configured to modify the received series of packets to disperse data corrupted from a first size to a second size based on the blockage impaired channel, and wherein the first size is associated with contiguous data and the second size is smaller than the first size.
9. The remote terminal of claim 8 , wherein:
wherein the received periodic unique identifiers are spaced at predetermined positions within the received series of packets.
10. The remote terminal of claim 8 , wherein to create the signal blockage indicator the correlation data remover is configured to:
correlate the received periodic unique identifiers with a copy of periodic unique transmission identifiers stored in a memory; and
create the signal blockage indicator when the correlation is below the threshold for a subset of the received periodic unique identifiers.
11. The remote terminal of claim 8 , wherein the deinterleaver comprises a set of delay lines and is configured to select a subset of delay lines based on the de-interleaving process.
12. The remote terminal of claim 8 , wherein the de-interleaving process is based on a configurable value stored at a register.
13. A method, comprising:
receiving a series of packets including periodic unique identifiers at a remote terminal;
determining that a correlation associated with the periodic unique identifiers is below a threshold for a subset of the periodic unique identifiers;
removing the periodic unique identifiers from the series of packets based on the determination; and
deinterleaving the series of packets following removing the periodic unique identifiers, wherein deinterleaving the series of packets further comprises delaying the series of packets by a first amount, the first amount associated with a second amount of delay associated with an interleaving process performed on the series of packets.
14. The method of claim 13 , wherein determining the correlation associated with the periodic unique identifiers is below the threshold further comprises:
correlating the periodic unique identifiers with a copy of the periodic unique identifiers stored at the remote terminal.
15. The method of claim 13 , further comprising:
modifying operation of the remote terminal for a portion of the series of packets associated with the subset of the periodic unique identifiers before deinterleaving the series of packets.
16. A method, comprising:
receiving a series of packets including periodic unique identifiers at a remote terminal;
determining that a correlation associated with the periodic unique identifiers is below a threshold for at least a portion of periodic unique transmission identifiers;
removing the periodic unique identifiers from the series of packets based on the determination;
deinterleaving the series of packets following removing the periodic unique identifiers; and
decoding the series of packets following the deinterleaving, wherein decoding the series of packets comprises:
a first decoding of the series of packets following the deinterleaving using a first decoder; and
a second decoding of the series of packets using a second decoder following the first decoding.