The least squares solution of a complex linear equation is in general a complex vector with independent real and imaginary parts. In certain applications in magnetic resonance imaging, a solution is desired such that each element has the same phase. A direct method for obtaining the least squares solution to the phase constrained problem is described. © 2010 Elsevier Inc. All rights reserved.
Bydder, M. (2010). Solution of a complex least squares problem with constrained phase. Linear Algebra and Its Applications, 433(11–12), 1719–1721. https://doi.org/10.1016/j.laa.2010.07.011