Direct-Sequence Spread-Spectrum Demodulator 60 Mchips/s

KEY FEATURES

Direct-Sequence Spread-Spectrum (DSSS) demodulation with flexible configuration:

Variable chip rate up to 60 Mchips/s
Speading factor 3 to 2047
Maximum processing gain: 33 dB
BPSK, QPSK selectable
Programmable center frequency

Spreading codes:

Gold sequences
Maximal length sequences
Barker codes (length 11, 13)
GPS C/A codes
Truncated codes
Code period can be (significantly) longer than symbol period: Maximal code period: 65535

Demodulation performances: within 1.5 dB from theory at threshold Eb/No of 2 dB

30-bin parallel code search for fast code acquisition. False code lock prevention

Accurate time of arrival pulse generated once per code period (can be used for round-trip delay measurement for example)

Monitoring:

Bit error rate
Receiver lock
Carrier frequency error
SNR

Demodulator data outputs: 4-bit soft-quantized to

Synchronous serial interface, or
USB 2.0, or
GbE LAN / TCP-IP socket (through COM-5102 LAN adapter)

ComScope-enabled: key internal signals can be captured in real-time and displayed on the host computer

Connectorized 3”x 3” module for ease of prototyping. Single 5V supply with reverse voltage and overvoltage protection. Interfaces with 3.3V LVTTL logic

ComBlock COMPATIBILITY LIST

Input	Output
COM-300x RF/IF/Baseband receivers	COM-1509 Convolutional error correction codec, K=5,7,9
COM-1824 Channel Emulator (Doppler, delay, fading, noise)	COM-7003 Turbo code error correction decoder
COM-5102 Gigabit Ethernet LAN adapter	COM-300x RF/IF/Baseband receivers
	COM-3504 Dual Analog<->Digital Conversions, 16-bit 250MS/s DACs, 12-bit 150 MS/s ADCs