Each user feeds back the CSI to its corresponding CTP via a feedback channel, and the instantaneous CSI can be exchanged reliably and fast between the two CTPs.
We consider a downlink multi-user OFDM system, in which two CTPs coordinately transmit their power to the coordinative zone users as depicted in Figure 1.
To sum up it is possible to conclude that, under the perfect coordinated transmission between two CTPs, the proposed JMPC-PA scheme provides an important improvement in the total power consumption of the system.
In order to simplify the mathematical derivation, we assume that the two CTPs have the same power constraint P0, and that they share the same overall bandwidth B, which is divided into N orthogonal narrow-band subcarriers.
Note that this set of values verifies Lemma 2, that stated that the optimal power allocation is obtained on the domain boundary, when only one of the available subchannels is being used simultaneously by the two CTPs.
Based on the above analysis, the optimal power allocation mode (as depicted in Figure 2) is that only one of the N-subchannels (i.e., a certain A n ) should be transmitted together by the two CTPs; the others, according to the different subchannel gains, should be separated into two parts (i.e., x1,jor x2,j) and transmitted by an individual CTP. Figure 2 Optimal power allocation mode.
Forty two CTP maps were described as normal (no abnormalities), 33 maps showed syndromes of ischemic strokes with various severities.
Figure 1 illustrates the five CTp characteristics obtained for a single patient at the end of the acquisition duration.
Mean values for four CTp parameters (permeability surface, PS; mean transit time, MTT; blood volume, BV; and blood flow, BF) were obtained and recorded for each patient.
Figure 5c illustrates the CTP approach which is represented by three CTPs only, including the BS.
