Citation
Abstract
The concept of a generalized data pre-processor for preliminary estimates of block and convolutionally encoded symbols is described and evaluated. Preliminary data estimates are envisioned to have application in removing binary phase-shift-keyed (BPSK) modulated data from the received carrier prior to phase estimation, particularly in low signal-to-noise ratio (SNR) environments where squaring losses impose a limit on estimator performance. Reception of weak signals from distant spacecraft, emergency-mode communications, and signals generated by small antenna elements of a larger array provide practical examples of where this technique can be used to improve overall system performance. Examples illustrating the potential improvements in carrier recovery are evaluated using both analysis and system-level simulation. The simulations include realistic block and convolutionally coded signals of the type often encountered in practice, such as extended Hamming and extended Bose-Chaudhuri-Hocquenghem (BCH) codes, along with short constraint-length convolutional codes generally employed in turbo codes. It is shown that received signal power can be reduced by as much as 6 dB when this technique is employed, implying a similar reduction in required transmitter power or antenna area on the spacecraft.
Keywords
Details
- Volume
- 42-144
- Published
- February 15, 2001
- Pages
- 1–19
- File Size
- 256.4 KB