Near-far Problem of Hybrid DS/SFH-SSMA with Multi-level Power Control
Takaya Yamazato, Yasuhiko Shinkaji, Masaaki Katayama, Akira Ogawa · International Symposium on Information Theory and its Applications · 1994
This paper investigates the bit error rate (BER) performance of hybrid direct-sequence/slow-frequency-hopping spread-spectrum multiple-access (DS/SFH-SSMA) operating in the environment with the near-far problem. We introduce a multi-level power control to mitigate the near-far problem on direct-sequence (DS) portion of DS/SFH system. Rate 1/2 convolutional code of constrain length 7 is applied with an appropriate interleaver. As a result, we found that the BER performance of DS/SFH system was always satisfactory in the presence of near-far problem and showed that with 4-level transmission power control, we can neglect the effect of near-far problem.