KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Access type: UnknownAuthor: search.filters.author.Kimpan, C.

Search Results

Now showing 1 - 8 of 8
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Analysis of forward-link capacity for DS-CDMA cellular system with power control strategy
    (2002-12-01)
    Longpichai, S.
    ;
    Rattanakoch, W.
    ;
    Kimpan, C.
    ;
    Pin-ngern, O.
    ;
    Noppanakeepong, S.
    In this paper, we analyze the forward-link capacity of a cellular DS-CDMA system, especially effect of power control strategy and orthogonality factor (f<inf>o</inf>) of multipath fading on the system. The problem of finding an optimum power control factor (n) is evaluated. According to n, the proper threshold distance is estimated for optimum performance. With these factors, the numerical results show that the capacity is reduced by changing f<inf>o</inf> from 0.7 to 0.2.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Blocking probability of the reverse link cellular CDMA system
    (2002-01-01)
    Kumpairee, C.
    ;
    Kimpan, C.
    ;
    Pin-Ngern, O.
    ;
    Hemmakorn, N.
    ;
    Noppanakeepong, S.
    The blocking probability of the reverse link cellular CDMA system is presented. Gaussian and lognormal approximation are the methods for determination of blocking probability. In the analysis in this paper, the parameter for the number of resolvable paths over a Rayleigh multipath fading channel is presented. In addition, we also show the effect of power control errors.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    On the algorithm for adaptive noise canceller with parallel block structure
    (2002-01-01)
    Kidakorn, P.
    ;
    Rattanakoch, W.
    ;
    Kimpan, C.
    ;
    Pin-Ngern, Ouen
    ;
    Noppanakeepong, S.
    An adaptive algorithm for detecting a single sinusoid of unknown frequency corrupted by Gaussian noise was proposed by Nishimura et al. (Trans. IEICE, vol. J72-A, no. 5, pp.786-794, 1989) using a IIR band pass filter with a variable center frequency and parallel block structure for fast processing. In 1996 an adaptive algorithm was investigated which solved the problem whereby the presence of several input frequencies led to the situation of it being impossible to achieve convergence using the new algorithm proposed by Takahashi et al. (Proc. IEEE APCCAS'94, pp. 376-381, 1994). However, the control signal generated by the new algorithm, used for adjusting the center frequency of the band pass filter, still jitters in spite of its convergence. In this paper, in addition to using the output in an adaptive algorithm as proposed, the input signal is used as an auxiliary or reference signal. In this way the jitter on the control signal can be reduced significantly, with the same convergence rate, with little added computational complexity.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Effect of multipath fading on the Erlang capacity of imperfect power control in cellular CDMA system
    (2002-01-01)
    Omsin, S.
    ;
    Manyanon, A.
    ;
    Kimpan, C.
    ;
    Pin-Ngern, O.
    ;
    Noppanakeepong, S.
    This paper presents an approach to the evaluation of the reverse link capacity of a cellular CDMA system, which is based on using Gaussian and lognormal approximations. We include the fading channel multipath intensity profile (MIP) shape factor in the Erlang capacity formula. Imperfect power control and Rayleigh multipath fading channels are considered.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Capacity analysis of forward-link in DS-CDMA cellular system with power control
    (2002-01-01)
    Longpichai, S.
    ;
    Rattanakoch, W.
    ;
    Kidakorn, P.
    ;
    Kimpan, C.
    ;
    Pin-Ngern, O.
    In this paper, we analyze the forward-link capacity of a cellular DS-CDMA system, especially the effects of power control, path loss exponent (γ) and orthogonality factor (f<inf>0</inf>) of multipath propagation on the system. The problem of finding an optimum power control factor (n) is evaluated. According to n, the proper threshold distance is estimated for optimum performance. With these factors, the numerical results show that the capacity is reduced by changing f<inf>0</inf> from 0.7 to 0.2 and γ from 5 to 3.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Outage probability, throughput and delay analysis of cellular DS-CDMA system in the presence of correlated signal and interference
    (2002-01-01)
    Rattanakoch, W.
    ;
    Kimpan, C.
    ;
    Pin-Ngern, Ouen
    ;
    Noppanakeepong, S.
    In this paper, we evaluate the performance of a cellular DS-CDMA system, by taking into account the correlation between signal and interference, to determined outage probability, throughput and delay for the reverse link with power control error. The numerical results show that when the correlation is considered the outage probability decreased, the throughput value increased, that is, the performance can be achieved.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Outage probability of the overlapped carriers allocation scheme with imperfect power control in DS-CDMA
    (2002-01-01)
    Techotchawan, A.
    ;
    Leepila, R.
    ;
    Kimpan, C.
    ;
    Thitimajshima, P.
    ;
    Noppanakeepong, S.
    The outage probability is investigated in cellular FD/CDMA (frequency division/code division multiple access) in terms of the SNR under the overlapped carrier allocation scheme in the reverse link of a cellular radio system, which is based on using Gaussian and lognormal approximations, respectively. In numerical results, the bandlimited pulse generated by raised cosine pulse shaping filters (SRRC) of the transmitted signal is investigated and compared in conventional FD/CDMA and OC-CDMA (overlapping carrier CDMA) for the outage probability. It is also shown that the outage probability can be improved by overlapping of carriers.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Multiple critical pole maximally flat RC active filter with sharp cutoff
    (1986-01-01)
    Thajchayapong, P.
    ;
    Kimpan, C.
    ;
    Rungsunseri, Y.
    A maximally flat RC active filter with sharp cutoff can be achieved by including single or multiple pairs of coincident transmission zeros but at the expense of high Q-factor of the critical pole pair. A novel design technique is proposed here to reduce the Q-factor of such filters by increasing the multiplicity of the critical pole pairs. Hence a new class of sharp cutoff maximally flat RC active filters with low sensitivity is obtained. © 1986, The Institution of Electrical Engineers. All rights reserved.