Page 329 - Kaleidoscope Academic Conference Proceedings 2024
P. 329

Innovation and Digital Transformation for a Sustainable World





                     10 7                                     efficiency, thus increasing the offloading capability and the
                  2.5
                        NOMA IRS with Partial offloading,B=2MHz  total computational bits.
                        OMA IRS with Partial offloading,B=2MHz
                        NOMA IRS with Partial offloading,B=4MHz  Fig.6 presents the total computational bits versus the
                   2    OMA IRS with Partial offloading,B=4MHz  iterations under different number of receiving antennas at
                 Total computation bits(bits)  1.5 1          that under different antenna numbers, the total computational
                                                                                   max
                                                                                      = 30dBm. It can be observed
                                                              AP. We set    = 40 and   
                                                                                     
                                                              bits can converge within 7 iterations, and the value after
                                                              4 iteration is already close to the final converged value.
                                                              This validates that the proposed algorithm can converge
                                                              computational bits improves as    increases.
                  0.5                                         quickly and effectively. Besides, we can see that the total
                                                                              5.  CONCLUSION
                   0
                   2      4      6      8      10    12
                             Number of AP antennas M          In this paper, we considered a MISO-based MEC system
                                                              with IRS. To assess the computational performance, we
           Figure 5 – The total computational bits versus the number of
                                                              studied the joint receiver beamforming, CPU frequency,
           receiver antennas   .
                                                              transmission power, and the IRS phase shifts problem to
                     6
                    10                                        maximize the computation rate.  An AO algorithm was
                 10
                       M=2                                    developed to solve the challenging non-convex problem.
                       M=4
                  9    M=6                                    Firstly, we split the orginal problem into four subproblems
                       M=8
                  8 7                                         and then solve the subproblems alternatively. Then, closed
                 Total computation bits(bits)  6 5            beamforming matrix and CPU frequency.  Finally, we
                                                              form optimal solution were derived to optimize receiver
                                                              exploited SCA-based iterative algorithm and SDR-based
                                                              iterative algorithm to optimize transmission power and IRS
                                                              phase shifts, respectively. It was proved that our proposed
                                                              computational performance compared to four benchmark
                  3 4                                         MISO-based MEC system with IRS can achieve superior
                                                              schemes.
                  2
                                                              The substantial gains in computational rate achieved by the
                  1
                   0    1    2    3    4    5    6    7       proposed system highlight its potential to support emerging
                                  Iterations
                                                              applications with computation-intensive and delay-sensitive
                                                              in B5G/6G networks. For example, in augmented reality
           Figure 6 – The total computational bits versus the iterations.
                                                              services, the enhanced computational capacity can enable
           total computational bits increases with   , which clearly  real-time rendering of high-quality graphics and seamless
           demonstrates that the proposed scheme and the IRS-aided full  user interaction. In intelligent transportation systems, the
           offloading scheme with NOMA exhibit consistent trends. The  reduced latency can facilitate real-time processing of vast
           reason is that the addition number of    can further improve  sensor data for rapid decision-making in autonomous driving.
           the offloading efficiency, thereby effectively improving the
           computational offloading performance. Moreover, IRS plays           REFERENCES
           a vital part in improving computational bits, as it can increase
           the transmission rate and thus enhancing the computational  [1] F. Fang, K. Wang, Z. Ding, and V. C. Leung,
                                                                  “Energy-efficient resource allocation for noma-mec
           offloading performance.
                                                                  networks with imperfect csi,” IEEE Transactions on
           Fig.5 plots the total computational bits versus    under  Communications, vol. 69, no. 5, pp. 3436–3449, 2021.
           different bandwidths    and transmission strategies. We can
                                                               [2] L. A. Haibeh, M. C. Yagoub, and A. Jarray, “A survey
           observe that the total computational bits increases with the
                                                                  on mobile edge computing infrastructure:  Design,
           bandwidth increases. This is because introducing MISO and
                                                                  resource management, and optimization approaches,”
           optimizing the receive beamforming matrix can effectively
                                                                  IEEE Access, vol. 10, pp. 27 591–27 610, 2022.
           improve the system capacity, enhancing the offloading
           efficiency. Meanwhile, increasing the number of antennas
                                                               [3] B. Ji, Y. Wang, K. Song, C. Li, H. Wen, V. G. Menon,
           and bandwidth improves the offloading efficiency, thereby
                                                                  and S. Mumtaz, “A survey of computational intelligence
           enhancing the overall system performance.  In addition,
                                                                  for 6g: Key technologies, applications and trends,”
           we can see that the NOMA-based scheme significantly
                                                                  IEEE Transactions on Industrial Informatics, vol. 17,
           outperforms the partial offloading scheme with OMA in
                                                                  no. 10, pp. 7145–7154, 2021.
           terms of the total computational bits. The reason is that
           under the same bandwidth, compared to OMA, NOMA     [4] F. Zhou and R. Q. Hu, “Computation efficiency
           transmission strategy can dramatically improve the spectral  maximization  in  wireless-powered  mobile  edge
                                                          – 285 –
   324   325   326   327   328   329   330   331   332   333   334