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- Hammarberg, Peter, et al.
(författare)
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Coded IDMA system performance with parallel interleavers
- 2010
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Ingår i: [Host publication title missing]. - 9781424470693 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- In this paper we evaluate the use of parallel interleavers for user separation in coded IDMA systems. The parallel interleavers have previously been evaluated for uncoded systems, and we here present extended results for the coded case. The new results are important for real systems, as they will most likely use performance enhancing channel coding. The parallel interleavers are designed to remove the risk of memory access collision during interleaving. These problems may occur when the interleaving process is being parallelized in order to support parallel processing at the decoder. The results show that the degree of parallelization in the interleaver design has an insignificant effect on the considered coded system performance. Furthermore, our results also show that the use of parallel interleavers gives a performance that is similar to that obtained when using random interleavers.
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| 2. |
- Khanzadi, M Reza, 1983, et al.
(författare)
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A Novel Cognitive Modulation Method Considering the Performance of Primary User
- 2010
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Ingår i: Wireless Advanced (WiAD), 2010 6th Conference on. - 9781424470693 ; , s. 1 - 6
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a new modulation method foran uncoded cognitive transmission (secondary user transmission)in presence of a Primary User (PU) for the AWGN channel.Interference of the PU is assumed to be known at the transmitterof Cognitive User (CU) non-causally. Based on this knowledge,for the design of the modulator and demodulator of the CU,a symbol by symbol approach is studied which can fulfill thecoexistence conditions of the CU and the PU of the band. In thisscheme, the modulator and demodulator of CU are designedjointly by solving an optimization problem to mitigate theinterference of the PU and minimize the symbol error probability(Pe) in CU’s communication link without increasing the symbolerror probability (Pe) of the PU. The proposed method is amodulation approach in a single (complex-valued) dimensionrather than a high dimensional coding scheme. Although thisone-dimensional method is not capacity achieving, we show it stillhas a remarkable performance with low amount of complexity.An implementation algorithm for our modulation method is alsopresented and the performance of this method is evaluated byexperimental results.
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