Otherwise, when the data is offloaded for edge execution (xti = 1), we denote Pit as the transmit power constrained by the maximum power Pt ≤ Pmax and τtT as the amount of time iii allocated to the ith WD for computation offloading. Here, τit ∈ [0, 1] and 􏰎Ni=1 τit ≤ 1. The energy consumed on data offloading is Eit,O = PitτitT. Similar to [4] and [8], we neglect the delay on edge computing and result downloading such that the amount of data processed at the edge within the time frame is Dt =WτitTlog 􏰈1+Pithti􏰉=WτitTlog 􏰈1+Eit,Ohti􏰉, ∀xt =1, (2) i,O vu 2 N0 vu 2 τitTN0 I，为什么要log2

在式子中，log2是为了将无线信道的信噪比（SNR）转换为信道容量，即单位时间内可以传输的比特数。在这个式子中，log2(1+Pithti/N0)表示接收端可以接收到的信号功率，其中N0是噪声功率。因此，log2(1+Pithti/N0)表示接收端可以传输的比特数，即信道容量。而WτitT是数据量，因此将它们相乘就得到了单位时间内可以传输的比特数。