Performance Analysis of UABS Assisted Heterogeneous Network for Disaster Management

Channel capacity analysis of non-orthogonal multiple access and massive multiple-input multiple-output wireless communication networks considering perfect and imperfect channel state information

“…Decoding starts with the highest channel gain for the user. Following the principles of duality, 37,48,50 receivers, 37,48 respectively. Highly complex dirty paper coding [51][52][53][54] is involved in the D/L dual of the U/L power control and maximal ratio combining successive interference cancellation.…”

“…For example, we can modify p 1 and p 2 to minimize B sum when ρ 1 and ρ 2 are fixed, 42,43 or to maximize X sum when ρ 1 and ρ 2 are adjustable, 43 or alternatively to maximize the sum log-rate log(ρ 1 ) + log(ρ 2 ) for better user fairness. 2,25,26,[44][45][46][47][48][49][50] In a MIMO system with N → ∞, maximal ratio combiner-successive interference cancellation is asymptotically approaching capacity. 24 We categorize maximal ratio combiner successive interfece cancellation as NOMA because multi-user detection (in the form of successive interference cancellation) and zeroforcing as orthogonal MA are required because single-user detection is required only.…”

“…In the analysis, flexible length time division is considered, in which we optimize the time slots for getting a better average sum rate among different cellular users. 37,[45][46][47][48]51 Firstly, we consider the equal energy constrained optimization where different powers are allocated to different users, but the sum of the total energy/frame will remain same.…”

“…For example, we can modify p 1 and p 2 to minimize B sum when ρ 1 and ρ 2 are fixed, 42,43 or to maximize X sum when ρ 1 and ρ 2 are adjustable, 43 or alternatively to maximize the sum log-rate log ( ρ 1 ) + log ( ρ 2 ) for better user fairness. 2,25,26,44…”

Sum rate capacity of non-orthogonal multiple access scheme with optimal power allocation

“…The orthogonal block can be a subcarrier, time slot, or spreading code in which more than one user can access a single resource. [5][6][7] This gives significant advantage over orthogonal multiple access (OMA) schemes, where a single user is served in each orthogonal block leading to very poor SE. In OMA, if a user has poor channel conditions, even then the scarce bandwidth is solely occupied by this user for fairness purposes, even though a high-priority user is required to be served who is waiting for the resource to be allocated to him.…”