The optimum performance of a closed loop transmission scheme depends upon perfect feedback information at the transmitter. The perfect feedback requires unlimited resources in the reverse communication link. However, ...
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ISBN:
(纸本)9781479944828
The optimum performance of a closed loop transmission scheme depends upon perfect feedback information at the transmitter. The perfect feedback requires unlimited resources in the reverse communication link. However, the feedback resources are limited in a practical system. Therefore, there is a trade off between the feedback load and the performance of transmission scheme. In this work, we evaluate the performance of multi user inter cell interference alignment (MUICIA) based transmit precoding scheme in a downlink MIMO system. It has been shown that in a system with unlimited feedback resources, MUICIA outperforms state of the art transmit precoding schemes. Here we assess the gains of MUICIA in a limited feedback uplink which is an important step in realization of this transmission scheme in practical systems. We consider two vector quantization based feedback designs. One is based on random generation of codebooks and the other is based on hierarchical codebooks.
We address the issue of interference in co-channel heterogeneous cellular networks where low-power pico cells are overlaid on high-power macro cells. Interestingly, unlike homogeneous networks, the co-channel heteroge...
详细信息
ISBN:
(纸本)9781479944828
We address the issue of interference in co-channel heterogeneous cellular networks where low-power pico cells are overlaid on high-power macro cells. Interestingly, unlike homogeneous networks, the co-channel heterogeneous networks exhibit special interference characteristics. This stems due to the transmit power mismatch in macro and pico layers. Interference alignment is one of the techniques that has been proposed to manage the interference in homogeneous macro cellular networks. Hence it is important to analyse the impact of power mismatch on interference alignment in the heterogeneous networks. For this purpose, we assess the performance of multi user inter cell interference alignment based transmit precoding scheme with different user selection methods in a heterogeneous network scenario. The results for pico cells show that the interference alignment based transmitprecoding is well supported by the alignment based user selection method. Additionally, we compare the performance of alignment based transmitprecoding with the state of the art non-alignment based precodings. We find that interference alignment is more robust to the power mismatch than its non-alignment based counterparts. This suggests that interference alignment can also be exploited as interference management scheme in co-channel heterogeneous networks.
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