  We consider codebooks of Complex Grassmannian Lines consisting of Binary
Subspace Chirps (BSSCs) in $N = 2^m$ dimensions. BSSCs are generalizations of
Binary Chirps (BCs), their entries are either fourth-roots of unity, or zero.
BSSCs consist of a BC in a non-zero subspace, described by an on-off pattern.
Exploring the underlying binary symplectic geometry, we provide a unified
framework for BSSC reconstruction---both on-off pattern and BC identification
are related to stabilizer states of the underlying Heisenberg-Weyl algebra. In
a multi-user random access scenario we show feasibility of reliable
reconstruction of multiple simultaneously transmitted BSSCs with low
complexity.
