Part of the spatial-diversity roadmap #127. Depends on #B.
Goal
Add number of active chains as a lever to the energy-minimizing adaptive link
(docs/adaptive-link.md), which today has modulation, bandwidth, and TX-power
knobs but no spatial knob.
The tradeoff
Each active chain adds always-on baseline draw, while coherent multi-chain
combining lets each chain drop its PA power for a target EIRP (total PA power
scales ~1/N). Since the adaptive-link thesis is that baseline dominates and PA is
a weak energy lever, the PA saving is partly eaten by the extra chains' baseline —
so there is an optimal chain count per range, a convex tradeoff the
energy-min controller is built to solve.
Scope
- Add a per-chain baseline + PA term to the adaptive-link energy model and derive
the optimal active-chain count as a function of path loss.
- Extend the controller to select chain count alongside the existing knobs, with a
graceful spatial staircase (collapse to 1 chain near the operator; light up chains
at range).
- Report energy-per-delivered-bit with the spatial lever added vs the current model.
Part of the spatial-diversity roadmap #127. Depends on #B.
Goal
Add number of active chains as a lever to the energy-minimizing adaptive link
(
docs/adaptive-link.md), which today has modulation, bandwidth, and TX-powerknobs but no spatial knob.
The tradeoff
Each active chain adds always-on baseline draw, while coherent multi-chain
combining lets each chain drop its PA power for a target EIRP (total PA power
scales ~1/N). Since the adaptive-link thesis is that baseline dominates and PA is
a weak energy lever, the PA saving is partly eaten by the extra chains' baseline —
so there is an optimal chain count per range, a convex tradeoff the
energy-min controller is built to solve.
Scope
the optimal active-chain count as a function of path loss.
graceful spatial staircase (collapse to 1 chain near the operator; light up chains
at range).