Squeezed-coherent BPSK c-q modulation format[1]
Alternative names: Displaced-squeezed BPSK c-q modulation format, Squeezed-state BPSK c-q modulation code, Squeezed-state BPSK c-q modulation scheme, Squeezed-state BPSK c-q signaling format, Two-photon coherent-state BPSK c-q modulation format.
Description
Bosonic c-q binary modulation format whose codewords are antipodal displaced-squeezed states, i.e., states of the form \(D(\pm\alpha)S(\zeta)|0\rangle\) for a common squeezing parameter \(\zeta\). The format was originally formulated using the term two-photon coherent states (TCS), an early name for squeezed states.Protection
Optimizing the displacement and squeezing for fixed mean photon number \(N\) changes the coherent-state BPSK overlap exponent from \(4N\) to \(4N(N+1)\) [1; Eq. (3.41)]. Thus, in the ideal binary pure-state discrimination expression, the coherent-state BPSK factor \(\exp[-4N]\) is replaced by \(\exp[-4N(N+1)]\).Rate
The c-q capacity of squeezed-state modulation over a pure-loss bosonic channel with coherent homodyne or heterodyne receivers, including closed-form optima for homodyne detection, was studied in Ref. [2; Ch. 5].Decoding
Homodyne detection realizes the field-quadrature measurement advantage of antipodal TCS signals in the ideal model [1].Homodyne and heterodyne receivers for squeezed-state modulation are treated in Ref. [2; Ch. 5].Cousin
- Squeezed cat code— Squeezed-coherent BPSK c-q modulation transmits classical information using displaced-squeezed states, while squeezed cat codes store quantum information in superpositions of squeezed coherent states.
Member of code lists
Primary Hierarchy
Parents
Squeezed-coherent BPSK c-q modulation format
Children
Squeezed-coherent BPSK c-q modulation reduces to coherent-state BPSK c-q modulation when the squeezing parameter is zero.
References
- [1]
- J. Shapiro, H. Yuen, and A. Mata, “Optical communication with two-photon coherent states–Part II: Photoemissive detection and structured receiver performance”, IEEE Transactions on Information Theory 25, 179 (1979) DOI
- [2]
- S. Guha, “Classical capacity of the free-space quantum-optical channel”, S.M. thesis, Massachusetts Institute of Technology (2004), URL
Page edit log
- Saikat Guha (2026-05-26) — most recent
- Victor V. Albert (2026-05-26)
Cite as:
“Squeezed-coherent BPSK c-q modulation format”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2026. https://errorcorrectionzoo.org/c/squeezed_coherent_bpsk