Suppression of Cochannel Interference in GSM by Pre-demodulation Signal Processing

نویسنده

  • William A. Gardner
چکیده

It is shown that FRESH (frequency-shift) filtering prior to Viterbi demodulation in GSM basestations and/or handsets can multiply the number of cochannel signals that can be separated with M antennas by (2M-1)/(M-1): suppression of 1 interferer with one antenna, 3 interferers with a diversity antenna pair, and 2M1 interferers with M antennas. The network-level simulations reported in this paper clearly demonstrate that FRESH filtering prior to demodulation in GSM basestations and/or handsets provides a cost-effective means of substantially improving system performance regardless of the antenna subsystem used. In all cases considered, single antenna, pair of diversity antennas, fully adaptive array of four omnidirectional antennas per 120° sector, and switched-beam array of four 30° antennas per 120° sector, FRESH filtering substantially reduces BER and FER (thereby improving quality) and/or reduces required SNR (thereby increasing range) and/or enables reduced frequency reuse factor (thereby increasing capacity).

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تاریخ انتشار 2008