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[Author] Young-Yong LEE(2hit)

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  • Forward Link Erlang Capacity of the IMT-2000 Hierarchical Cellular System with Mixed Traffic Rates

    Young-Yong LEE  Sang-Mun LEE  Hyung-Jin CHOI  

     
    PAPER

      Vol:
    E85-A No:6
      Page(s):
    1289-1298

    In this paper, the forward link erlang capacity and outage probability for hierarchical cellular system based on 2 layer macrocell/microcell are derived analytically by considering the impact of imperfect power control and soft hand-off. The analysis on the outage probability is carried out using two methods: lognormal approximation and Chernoff upper bound. We assume that voice and multi-rate data service users are distributed uniformly in each cell and the same spectrum is applied in both layers. In addition, we take into account the base station transmission power ratio between tiers and the relative position of microcell having island distribution in macrocell. The forward link interference is evaluated by using Monte-Carlo simulation introduced in [2]. In this paper, we compare the forward link erlang capacity of 1x system to 3x system and show that 3x system can increase the user capacity by 3.4 times in case of macrocell and microcell, respectively, compared to 1x system.

  • The Modified CP-AFC with Multi-Stage Tracking Mode for WCDMA Reverse Link Receiver

    Joo-Hyun DO  Young-Yong LEE  Hyung-Jin CHOI  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1397-1404

    In this paper, we propose a modified CP-AFC (Cross-Product Automatic Frequency Control) algorithm to enhance coherent signal detection for WCDMA reverse link receiver. We introduce a moving average filter at the FDD input to decrease the noise effect by increasing the number of cross-products, since pilot symbol in WCDMA is not transmitted continuously. We also add normalization algorithm to overcome the conventional CP-FDD's sensitivity to the variance of input signal amplitude and to increase the linear range of S-curve. For rapid frequency acquisition and tracking, we adopt a multi-stage tracking mode. We applied the proposed algorithm in the implementation of WCDMA base station modem successfully.