A. Al Amni, A. Li, S. Chen, X. Chen, G. Gao, W. Shieh, "Dual-LP$_{11}$ mode 4$\,\times\,$4 MIMO-OFDM transmission over
a two-mode fiber," Opt. Expr. 19, 16672--16678 (2011).

S. Randel, R. Ryf, A. Sierra, P. Winzer, A. H. Gnuack, C. Bolle, R.-J. Essiambre, D. W. Peckham, A. McCurdy, R. Lingle, "6$\,\times\,$56-Gb/s mode-division multiplexed transmission over 33-km few-mode
fiber enabled by 6$\,\times\,$6 MIMO equalization," Opt. Expr. 19, 16697-16707 (2011).

C. Koebele, M. Salsi, D. Sperti, P. Tran, P. Brindel, H. Margoyan, S. Bigo, A. Boutin, F. Verluise, P. Sillard, M. Bigot-Astruc, L. Provost, F. Cerou, G. Charlet, "Two mode transmission at 2$\,\times\,$100 Gb/s,
over 40 km-long prototype few-mode fiber, using LCOS based mode multiplexer
and demultiplexer," Opt. Expr. 19, 16593-16600 (2011).

K.-P. Ho, J. M. Kahn, "Statistics of group delays
in multimode fiber with strong mode coupling," J.
Lightw. Technol. 29, 3119-3128 (2011).

K.-P. Ho, J. M. Kahn, "Mode-dependent loss and gain:
Statistics and effect on mode-division multiplexing," Opt.
Expr. 19, 16612-16635 (2011).

P. J. Winzer, G. J. Foschini, "MIMO capacities and outage
probabilities in spatially multiplexed optical transport systems," Opt. Expr. 19, 16680-16696 (2011).

R. E. Freund, C.-A. Bunge, N. N. Ledentsov, D. Molin, C. Caspar, "High-speed transmission in multimode fibers," J. Lightw. Technol. 28, 569-586 (2010).

F. Yaman, N. Bai, B. Zhu, T. Wang, G. Li, "Long
distance transmission in few-mode fibers," Opt.
Expr. 18, 13250-13257 (2010).

M. B. Shemirani, W. Mao, R. A. Panicker, J. M. Kahn, "Principal modes in graded-index multimode
fiber in presence of spatial- and polarization-mode coupling," J. Lightw. Technol. 27, 1248-1261 (2009).

K.-P. Ho, "Subband equaliser for chromatic
dispersion of optical fibre," Electron. Lett. 45, 1224-1226 (2009).

E. Ip, A. P. T. Lau, D. J. F. Barros, J. M. Kahn, "Coherent detection in optical
fiber systems," Opt. Expr. 16, 753-791 (2008).

M. Nazarathy, A. Agmon, "Coherent transmission direct detection MIMO
over short-range optical interconnects and passive optical networks," J. Lightw. Technol. 26, 2037-2045 (2008).

A. Tarighat, R. C. J. Hsu, A. Shah, A. H. Sayed, B. Jalali, "Fundamentals and challenges of optical multiple-input
multiple-output multimode fiber links," IEEE
Commun. Mag. 57-63 (2007).

R. M. Gray, "Toeplitz and circulant matrices:
A review," Foundation Trends Commun. Inf. Theory 2, 155-239 (2006).

A. R. Shah, R. C. J. Hsu, A. Tarighat, A. H. Sayed, B. Jalali, "Coherent optical MIMO (COMIMO)," J. Lightw. Technol. 23, 2410-2419 (2005).

K. Liu, T. Kadous, A. K. Sayeed, "Orthogonal time-frequency signaling
over doubly dispersive channels," IEEE Trans.
Inf. Theory 50, 2583-2602 (2004).

X. Zhu, R. D. Murch, "Layered space-frequency equalization
in a single-carrier MIMO system for frequency-selective channels," IEEE Trans. Wireless Commun. 3, 701-708 (2004).

A. M. Tulino, S. Verdú, "Random matrix theory and wireless
communications," Foundation Trends Commun. Inf.
Theory 1, 1-182 (2004).

X. Ma, G. B. Giannakis, "Maximum-diversity transmissions
over doubly selective wireless channels," IEEE
Trans. Inf. Theory 49, 1832-1840 (2003).

P. K. Pepeljugoski, D. M. Kuchta, "Design of optical communications
data links," IBM J. Res. Dev. 47, 223-237 (2003).

N. Al-Dhahir, "Single-carrier frequency-domain
equalization for space-time block-coded transmissions over frequency-selective
fading channels," IEEE Commun. Lett. 5, 304-306 (2001).

M. Karlsson, "Probability density functions
of the differential group delay in optical fiber communication systems," J. Lightw. Technol. 19, 324-331 (2001).

H. R. Stuart, "Dispersive multiplexing in
multimode optical fiber," Science 289, 281-283 (2000).

V. Tarokh, H. Jafarkhani, A. R. Calderbank, "Space-time block codes from
orthogonal designs," IEEE Trans. Inf. Theory 45, 1456-1467 (1999).

D. A. Nolan, M. J. Li, "Fiber spin-profile designs for producing
fibers with low polarization mode dispersion," Opt.
Lett. 23, 1659-1661 (1998).

H. Sari, G. Karam, I. Jeanclaude, "Transmission techniques for digital terrestrial
TV broadcasting," IEEE Commun. Mag. 100-109 (1995).

W. Y. Zou, Y. Wu, "COFDM: An overview," IEEE
Trans. Broadcast. 41, 1-8 (1995).

K.-I. Kitayama, S. Sikai, N. Uchida, "Impulse response prediction based on experimental
mode-coupling coefficient in a 10-km long graded-index fiber," J. Quantum Electron. QE-16, 356-362 (1980).

R. Olshansky, "Mode-coupling effects in graded-index
optical fibers," App. Opt. 14, 935-945 (1975).

D. Gloge, "Optical power flow in multimode
fibers," Bell System Tech. J. 51, 1767-1780 (1972).

R. M. Gray, "On the asymptotic eigenvalue
distribution of Toeplitz matrices," IEEE Trans.
Inf. Theory IT-18, 725-730 (1972).

R. Olshansky, "Mode-coupling effects in graded-index
optical fibers," App. Opt. 14, 935-945 (1975).

D. Gloge, "Optical power flow in multimode
fibers," Bell System Tech. J. 51, 1767-1780 (1972).

K.-P. Ho, "Subband equaliser for chromatic
dispersion of optical fibre," Electron. Lett. 45, 1224-1226 (2009).

A. M. Tulino, S. Verdú, "Random matrix theory and wireless
communications," Foundation Trends Commun. Inf.
Theory 1, 1-182 (2004).

R. M. Gray, "Toeplitz and circulant matrices:
A review," Foundation Trends Commun. Inf. Theory 2, 155-239 (2006).

P. K. Pepeljugoski, D. M. Kuchta, "Design of optical communications
data links," IBM J. Res. Dev. 47, 223-237 (2003).

A. Tarighat, R. C. J. Hsu, A. Shah, A. H. Sayed, B. Jalali, "Fundamentals and challenges of optical multiple-input
multiple-output multimode fiber links," IEEE
Commun. Mag. 57-63 (2007).

W. Y. Zou, Y. Wu, "COFDM: An overview," IEEE
Trans. Broadcast. 41, 1-8 (1995).

X. Ma, G. B. Giannakis, "Maximum-diversity transmissions
over doubly selective wireless channels," IEEE
Trans. Inf. Theory 49, 1832-1840 (2003).

N. Al-Dhahir, "Single-carrier frequency-domain
equalization for space-time block-coded transmissions over frequency-selective
fading channels," IEEE Commun. Lett. 5, 304-306 (2001).

H. Sari, G. Karam, I. Jeanclaude, "Transmission techniques for digital terrestrial
TV broadcasting," IEEE Commun. Mag. 100-109 (1995).

K. Liu, T. Kadous, A. K. Sayeed, "Orthogonal time-frequency signaling
over doubly dispersive channels," IEEE Trans.
Inf. Theory 50, 2583-2602 (2004).

R. M. Gray, "On the asymptotic eigenvalue
distribution of Toeplitz matrices," IEEE Trans.
Inf. Theory IT-18, 725-730 (1972).

V. Tarokh, H. Jafarkhani, A. R. Calderbank, "Space-time block codes from
orthogonal designs," IEEE Trans. Inf. Theory 45, 1456-1467 (1999).

X. Zhu, R. D. Murch, "Layered space-frequency equalization
in a single-carrier MIMO system for frequency-selective channels," IEEE Trans. Wireless Commun. 3, 701-708 (2004).

K.-P. Ho, J. M. Kahn, "Statistics of group delays
in multimode fiber with strong mode coupling," J.
Lightw. Technol. 29, 3119-3128 (2011).

A. R. Shah, R. C. J. Hsu, A. Tarighat, A. H. Sayed, B. Jalali, "Coherent optical MIMO (COMIMO)," J. Lightw. Technol. 23, 2410-2419 (2005).

M. Nazarathy, A. Agmon, "Coherent transmission direct detection MIMO
over short-range optical interconnects and passive optical networks," J. Lightw. Technol. 26, 2037-2045 (2008).

R. E. Freund, C.-A. Bunge, N. N. Ledentsov, D. Molin, C. Caspar, "High-speed transmission in multimode fibers," J. Lightw. Technol. 28, 569-586 (2010).

M. Karlsson, "Probability density functions
of the differential group delay in optical fiber communication systems," J. Lightw. Technol. 19, 324-331 (2001).

M. B. Shemirani, W. Mao, R. A. Panicker, J. M. Kahn, "Principal modes in graded-index multimode
fiber in presence of spatial- and polarization-mode coupling," J. Lightw. Technol. 27, 1248-1261 (2009).

K.-I. Kitayama, S. Sikai, N. Uchida, "Impulse response prediction based on experimental
mode-coupling coefficient in a 10-km long graded-index fiber," J. Quantum Electron. QE-16, 356-362 (1980).

F. Yaman, N. Bai, B. Zhu, T. Wang, G. Li, "Long
distance transmission in few-mode fibers," Opt.
Expr. 18, 13250-13257 (2010).

K.-P. Ho, J. M. Kahn, "Mode-dependent loss and gain:
Statistics and effect on mode-division multiplexing," Opt.
Expr. 19, 16612-16635 (2011).

D. A. Nolan, M. J. Li, "Fiber spin-profile designs for producing
fibers with low polarization mode dispersion," Opt.
Lett. 23, 1659-1661 (1998).

P. J. Winzer, G. J. Foschini, "MIMO capacities and outage
probabilities in spatially multiplexed optical transport systems," Opt. Expr. 19, 16680-16696 (2011).

A. Al Amni, A. Li, S. Chen, X. Chen, G. Gao, W. Shieh, "Dual-LP$_{11}$ mode 4$\,\times\,$4 MIMO-OFDM transmission over
a two-mode fiber," Opt. Expr. 19, 16672--16678 (2011).

S. Randel, R. Ryf, A. Sierra, P. Winzer, A. H. Gnuack, C. Bolle, R.-J. Essiambre, D. W. Peckham, A. McCurdy, R. Lingle, "6$\,\times\,$56-Gb/s mode-division multiplexed transmission over 33-km few-mode
fiber enabled by 6$\,\times\,$6 MIMO equalization," Opt. Expr. 19, 16697-16707 (2011).

C. Koebele, M. Salsi, D. Sperti, P. Tran, P. Brindel, H. Margoyan, S. Bigo, A. Boutin, F. Verluise, P. Sillard, M. Bigot-Astruc, L. Provost, F. Cerou, G. Charlet, "Two mode transmission at 2$\,\times\,$100 Gb/s,
over 40 km-long prototype few-mode fiber, using LCOS based mode multiplexer
and demultiplexer," Opt. Expr. 19, 16593-16600 (2011).

E. Ip, A. P. T. Lau, D. J. F. Barros, J. M. Kahn, "Coherent detection in optical
fiber systems," Opt. Expr. 16, 753-791 (2008).

H. R. Stuart, "Dispersive multiplexing in
multimode optical fiber," Science 289, 281-283 (2000).

E. Lindskog, A. Paulraj, "A transmit diversity scheme
for delay spreads channel," Proc. IEEE ICC (2000) pp. 207-311.

K. F. Lee, D. B. Williams, "A space-frequency transmitter
diversity techniques for OFDM systems," IEEE
GlobeCom (2000) pp. 1473-1477.

T. S. Rappaport, Wireless Communications: Principles
& Practice (Prentice Hall, 2002).

Y. Koike, S. Takahashi, Optical Fiber Telecommunications
VB: Systems and Networks (Elsevier
Academic, 2008).

I. T. Jolliffe, Principal Component Analysis (Springer, 2002).

W. B. Davenport, W. L. Root, An Introduction to the Theory of
Random Signals and Noise (Wiley-IEEE, 1987).

M. Vetterli, J. Kovačević, Wavelets and Subband Coding (Prentice
Hall, 1995).

G. R. Grimmett, D. R. Stirzaker, Probability and Random Processes (Oxford Univ. Press, 1992).

D. Tse, P. Viswanath, Fundamentals of Wireless Communication (Cambridge
Univ. Press, 2005).

J. P. Gordon, H. Kogelnik, "PMD fundamentals: Polarization
mode dispersion in optical fibers," Proc. Natl.
Acad. Sci. (2000) pp. 4541-4550.

D. Marcuse, Theory of Dielectric Optical Waveguides (Academic Press, 1974).