low density parity check (ldpc) error correction system

ReinventingTelemetryINSTRUMENTATION DEVICES SRLVia Acquanera 29, 22100 COMO (Italy) tel. +39.031.525391 - fax +39.031.507984 - info@instrumentation.itwww.instrumentation.itLOW DENSITY PARITY CHECK (LDPC)ERROR CORRECTION SYSTEMThe Low Density Parity Check (LDPC) ForwardError Correction mode is a breakthrough additionto Quasonix transmitters and receivers. Improves Link Margin by 8.8 to 9.4 dB at BER = 1e-5Link margin improvement is equivalent to nearly tripling theoperating distance on your telemetry link Adaptive DecoderDecoding performance is within 0.2 dB of theoryIterative decoding is optimized to fully utilize available time,LDPC BER Performanceimproving coding gain even further as the bit rate is reduced Fully Integrated Forward Error Correction System6.0 in 3Transmitter automatically synthesizes expanded over-the-airbit rate for encoded blocks and receiver seamlessly convertsback to continuous output at the user bit rateOperation is completely transparent to data devices Robust SynchronizationReliable synchronization achieved as low as –4 dB Eb/N0TIMTER Uses Spectrally Efficient SOQPSK ModulationEven with the LDPC coding overhead (56.25%), bandwidth is22% less than PCM/FM at the same payload bit rate; Payloadbit rates up to 29.44 Mbps are supported Simple ON / OFF ControlAllows transmitter/receiver operation with or without correctionnanoTX Tested on a DoD RangeRDMS Rack Mount ReceiverAlready own Quasonix equipment?The LDPC mode can be retrofitted to most Quasonixtransmitters and receivers. Contact Quasonix for details.

LDPC FORWARD ERROR CORRECTION PERFORMANCEPerformance OverviewQuasonix is the only vendor in the market offering LDPC encoding and decoding for serial streaming telemetry. This approach yieldsnearly triple the communications range, yet it does so with 22% less bandwidth than conventional PCM/FM.Synchronization ThresholdThe best coding gain in the world won’t helpif the telemetry link cannot maintainsynchronization through extremely deepfades. Only Quasonix can consistently showsynchronization at negative Eb/N0 values,and the LDPC subsystem is no exception.The ability to preserve bit count integrity atEb/N0 as low as –4 dB allows the user’scrypto devices to stay synchronized underthe most severe fading conditions, therebyeliminating the long data outages that occurwhen the crypto devices lose sync.Not only does the LDPC subsystemmaintain synchronization under highlyadverse link conditions, but under worstcaselink conditions the re-synchronizationpenalty is at most one LDPC code block. Signal plus noise,synchronized at-3 dB Eb/N0Signal plus noise,error-free at+3 dB Eb/N0Strong signal,+35 dB Eb/N0Receiver IF Output During 7 Mb/s LDPC Operation2www.instrumentation.itINSTRUMENTATION DEVICES SRLVia Acquanera 29, 22100 COMO (Italy) tel. +39.031.525391 - fax +39.031.507984 - info@instrumentation.it