Design, Implementation and Evaluation of a Telemetry Channel Coding Sublayer

Abstract

Coding layer protects the transferred data frames against errors induced during transmission through the noisy physical communications channel and offers security to the transmitted data. The main objective of this paper is to evaluate the performance of a concatenated Reed-Solomon and convolutional code in a noisy space telemetry channel. To do so, data is encoded and decoded according to CCSDS recommendations. Coding sublayer is implemented in a Spartan3E series (XC3S500E) target device with use of VHDL as the hardware description language. In order to simulate the additive noise of the communication channel, we gradually reduced the signal level at the transmitter end. Experimental results revealed that the implemented error correction codes improved the SNR of the space telemetry link about 6 dB. In addition, the measured power consumption of the coding sublayer was about 200mW which is easily negligible in comparison to the power budget of the receiver board.
Key Words: Reed-Solomon code; Convolutional Encoder; Viterbi Decoder; CCSDS