The SNR is defined for the payload portion of each packet, that is, it is defined as the ratio of payload power over the noise variance.
Statistical power control (p_{lk} = frac {rho }{d_{l}(mathbf {z}_{lk})}) is still applied for pilots, while the uplink payload power τ jk is optimized.
Since the downlink payload power can be obtained according to Theorems 4 and 5, the optimized uplink SEs can also be achieved in the downlink.
Table 8 Overview of the total power budget for LTP and MAQRO Payload power required LTP MAQRO Payload, maximal 163 166 Total power required LPF MAQRO Spacecraft in transfer orbit 638 638 Spacecraft in science mode 613 613.
In this section, we provide a key application of the results from Theorem 3: joint uplink payload power control for sum SE maximization in multi-cell network.
As transmission experiments are performed during eclipse, the EPS must be able to support the payload power draw using battery reserves alone.
The computational efficiency and simplicity of the current approach offer a promising alternative to satisfying the payload, power and bandwidth constraints imposed by aerial microsystems.
It is pointed out in [19] that when the precoder is a scaled version of the detector, the same per-user SEs as in the uplink can be achieved in the downlink by properly selecting the downlink payload power.
where ({boldsymbol {Lambda }_{j}} = sum limits _{l in L} {sum limits _{k = 1}^{K} tau _{lk} p_{lk}d_{j}^{2}(mathbf {z}_{lk})} {mathbf {e}_{{i_{lk}}}}mathbf {e}_{{i_{lk}}}^{H} in mathbb {C}^{B times B}) is a diagonal matrix, and its ith diagonal element λ ji depends on the large-scale fading, the pilot and payload power of the users that use the ith pilot sequence in (mathcal {V}).
The first, published by Brad Edwards and Eric Westling in their 2003 book Space Elevators, envisaged 20-tonne payloads powered by Earth-based lasers travelling at a cost of $150 a kilogram, and with a construction price tag of $6bn £3.9bnn).
