Features Up to 8 Synchronizer Channels Up to 4 Best Source Group
Outputs Works with encrypted or non-encrypted data Input streams
automatically time correlated Seamless switching on bit boundaries
(down
-stream frame synchronizers will not drop lock due to
switching).
Signal Quality Selection Criteria Measured Long-Term Signal
Quality Measured Short-Term Signal Quality Synchronization Pattern
Detection Convolutional Decoding Bit Sync Lock and Signal
Present
Bit-by-Bit Majority Vote Weighted by Signal Quality Short Term
Bit-by-Bit Quality Long Term Stream Quality Bit-by-Bit Error
Correction 3.3 dB Improved Link Performance
Encapsulated Data Input* Signal Quality and Data from up to
eight
local or upstream synchronizers (e.g. MD2265EC, MD4426)
RCC DQM / DQE GDP Encapsulation
Up to 8 Internal Bit Synchronizers Bit Rates
5 bps to 20 Mbps (40 Mbps*)
BER Performance within 1 dB of theory Loop Bandwidth
Settings from 0.01% to 1.6%
Accepts NRZ-L/M/S, BiØ-L/M/S, DM-M/S; MDM-M/S
Randomizer / Derandomizer Scrambler / Descrambler
CCITT V.35/36
Viterbi Decoder Frame Pattern Detector Advanced Lock Detection
QPSK/OQPSK/SOQPSK Re-sequencer* Hot Swap Redundant Power Supplies
Remote Control and Monitoring
RS-232 Ethernet IEEE-488*
4 U Chassis *-Optional
Model 2266
Multi-Channel PCM Bit Synchronizer Correlating Best Source
Selector
747 Dresher Road · Suite 125 · Horsham, PA 19044-2247
www.gdpspace.com Phone: 215-657-5270 Fax: 215-657-5273
[email protected]
The GDP Model 2266 Multi-Channel PCM Bit Synchronizer /
Correlating Best Source Selector / Diversity Combiner provides
Seamless Bit-by-Bit Selections to correct individual errors in
source data streams. The error correction process functions just as
smoothly on clear or encrypted data streams. Up to eight
high-performance bit synchronizers may be user assigned to process
a mission group of signals. The group of streams are time
correlated so that seamless bit-by-bit switching may take place to
provide highly accurate data time-after-time. Each individual bit
synchronizer channel may be used as a normal Bit Synchronizer or
designated as a source within the Best Source Selection process.
The optimized digital design of this unit affords the highest
performance characteristics currently available. Software does not
take part in any critical function in the unit. When an input
signal is formed with complex functions, the MD2266 handles it
without the need for special programming or support hardware. The
normal course of telemetry signal handling includes: IRIG
randomizer / de-randomizer (both forward and reverse sequences),
CCITT V.35 and V.36 scrambling /descrambling, as well as Viterbi
decoding for std. R1/2 K7 and optional R3/4 K7 and R1/3 K7 (please
inquire for other FEC options). The ‘I’ and ‘Q’ signal outputs
produced by QPSK, OQPSK and SOQPSK demodulators may be optionally
re-sequenced into the original data streams. Best Source Selection
of Non-Encrypted and Encrypted Data based on Signal Quality and
Majority Voting In Summary: The GDP Space Systems MD2266 is the
most advanced, next generation implementation of a Telemetry
Correlating Diversity Combining Best Source Selector. Signal
Quality and Majority Voting are both used to determine the most
accurate output signaling. The unit does not need to see a
synchronization pattern to time correlate the input data streams.
Therefore, encrypted data may be processed as well as non-encrypted
data. A digital data / clock input mode is also available for the
cases where receivers are located remotely and the analog signal is
not available at the Best Source Selector. Regardless of the
processing mode, highly accurate best source selection is achieved
with as much as 3.3 dB of link performance gain.
MD2266B-XX Basic Unit (20Mbps) includes 1 BSS Group Majority
Vote also included in Base MD2266B -XX = -04, -06, -08 Channels
OP2266B-01 Extended Bit Rate 5 bps to 40 Mbps OP2266B-05 QPSK &
OQPSK Option OP2266B-06 SOQPSK Option OP2266B-07 QPSK & OQPSK
& SOQPSK
OP2266B-10 IEEE-488 Remote Control OP2266B-21 Ethernet Remote
Control OP2266B-40 Additional BSS Groups (up to 3 additional)
OP2266B-41 Special I/O Transition Module OP2266B-48 I/O Cables
(required when more than 8 channels) OP2266B-50 Redundant Power
Supply OP2266B-89 Rack Mount Shelf Kit
Specifications
Inputs per Channel Three (3) Analog or Digital [Other I/O
configurations Available] Input Impedance Lo Z: 50 Ohms (optional
75 Ohm) or High Z (Selectable) Signal Level 0.25 Vp-p to 12 Vp-p or
RS-422 (Optional) DC Offset 100% of the input peak-to-peak signal
level (not to exceed |12 V|). AC Offset No degradation up to 100%
of input signal amplitude at 0.1% of the bit rate. Input Codes
NRZ-L/M/S, BIǾ-L/M/S, DM-M/S, MDM-M/S De-randomizer RNRZ-L
De-randomizer fwd and rev per IRIG-106 Input Polarity Normal /
Inverted. Viterbi Decoder Constraint length 7, rate ½ (G1 =1718 G2=
1338) POR and ASI (other Viterbi options available) Eb/No
Measurement -3 dB to +15 dB 0.5 dB resolution Bit Rate Range 40 bps
to 20 Mbps (40 Mbps optional) Tuning Resolution of Bit Rate
X.XXXE
N (1≤N≤7)
Capture Range Equal to LBW Loop Bandwidths 0.01% to 1.6% Sync
Threshold SNR –3 dB for NRZ, (-1 dB for BIǾ) codes, square-sided
data. Sync Maintenance SNR –3 dB with transition density 50%, LBW=
1.0, NRZ-L Sync Acquisition 50 bits or less Sync Retention 256 bits
without transitions, LBW= 1.0 Bit Error Rate Within 1 dB of theory
over the full bit rate range Frame Pattern Detector Detection of up
to 32 bits
Outputs per Channel:
TTL: Two Coded PCM and Two Clocks (Programmable 0, 90, 180, 270
degrees), one port is Selected Data & Clock Output for BSS
Channels
RS422: Two Coded PCM and Two Clock (Programmable 0, 90, 180, 270
degrees), one port is Selected Data & Clock Output for BSS
Channels
Bipolar: One per Channel +/-1 V - Coded PCM
Lock Status: Composite Synchronization, Bit Sync, Frame Sync,
Viterbi Sync Signal Quality Status: Eb/No, Bit-Rate Deviation,
Frame Sync Status, Viterbi Sync Status, APC State,
Measured Bit Rate, Composite Sync Loss-Count, BER
Ordering Information
747 Dresher Road · Suite 125 · Horsham, PA 19044-2247
www.gdpspace.com Phone: 215-657-5270 Fax: 215-657-5273
[email protected] © 2013-2017 GDP Space Systems, Inc.
R180130
* Recognizing that no standard product can meet all the needs of
all users, GDP stands ready to provide units tailored to unique
applications. *The statements in this data sheet are not intended
to create any warranty, expressed or implied. Specifications are
subject to change without notice.
Model 2266B
Multi-Channel PCM Bit Synchronizer And Best Source Selector
