Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing
AbstractMassive multiple-input multiple-output (massive-MIMO) is foreseen as a potential technology for future 5G cellular communication networks due to its substantial benefits in terms of increased spectral and energy efficiency. These advantages of massive-MIMO are a consequence of equipping the base station (BS) with quite a large number of antenna elements, thus resulting in an aggressive spatial multiplexing. In order to effectively reap the benefits of massive-MIMO, an adequate estimate of the channel impulse response (CIR) between each transmit–receive link is of utmost importance. It has been established in the literature that certain specific multipath propagation environments lead to a sparse structured CIR in spatial and/or delay domains. In this paper, implicit training and compressed sensing based CIR estimation techniques are proposed for the case of massive-MIMO sparse uplink channels. In the proposed superimposed training (SiT) based techniques, a periodic and low power training sequence is superimposed (arithmetically added) over the information sequence, thus avoiding any dedicated time/frequency slots for the training sequence. For the estimation of such massive-MIMO sparse uplink channels, two greedy pursuits based compressed sensing approaches are proposed, viz: SiT based stage-wise orthogonal matching pursuit (SiT-StOMP) and gradient pursuit (SiT-GP). In order to demonstrate the validity of proposed techniques, a performance comparison in terms of normalized mean square error (NCMSE) and bit error rate (BER) is performed with a notable SiT based least squares (SiT-LS) channel estimation technique. The effect of channels’ sparsity, training-to-information power ratio (TIR) and signal-to-noise ratio (SNR) on BER and NCMSE performance of proposed schemes is thoroughly studied. For a simulation scenario of:
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Mansoor, B.; Nawaz, S.J.; Gulfam, S.M. Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing. Appl. Sci. 2017, 7, 63.
Mansoor B, Nawaz SJ, Gulfam SM. Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing. Applied Sciences. 2017; 7(1):63.Chicago/Turabian Style
Mansoor, Babar; Nawaz, Syed J.; Gulfam, Sardar M. 2017. "Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing." Appl. Sci. 7, no. 1: 63.
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