Modified Orthogonal Space-Time Block Codes for Time-Selective Fading Channels

• Published in: IEEE transactions on vehicular technology Vol. 57; no. 6; pp. 3921 - 3927
• Main Authors: Villardi, Gabriel Porto, De Abreu, Giuseppe T. F., Kohno, Ryuji
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Applied sciences; Bit error rate; Block codes; Channels; Coding, codes; Computer simulation; Decoding; Degradation; Exact sciences and technology; Fading; Information, signal and communications theory; Mathematical analysis; Modulation; Modulation, demodulation; Molybdenum; Orthogonal space-time block codes (O-STBCs); Phase modulation; Phase shift keying; Quadrature amplitude modulation; Radiocommunications; self-interference; Signal and communications theory; Statistical analysis; Statistics; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; time-selective fading channels; Transmission and modulation (techniques and equipments); transmit diversity; Orthogonal space-time block codes; time-selective fading channels; transmit diversity; self-interference; Fading channels; Performance evaluation; Block code; Space-time codes; Gray code; Quadrature amplitude modulation; Computer simulation; Bit error rate; Amplitude modulation; Decoding circuit; Decoding; Orthogonality; Degradation; Phase shift keying; Selective fading; M ary modulation; Algorithm complexity; Orthogonal space-time block codes (O-STBCs); self- interference; Antenna; Damaging
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2008.918697

We consider orthogonal space-time block codes (O-STBCs) in time-selective fading channels and propose a modified O-STBC (MO-STBC), which is less subject to the performance degradation caused by symbol-by-symbol channel variation. It is shown both analytically and through computer simulations that MO-STBCs effectively reduce the loss of orthogonality affecting O-STBCs in the symbol-by-symbol time-selective channel. MO-STBCs are systematically constructible for any number of antennas and have the same decoding complexity of conventional O-STBCs. The bit-error-rate (BER) performance of MO-STBCs over time-selective fading channels of generalized statistics, with Gray-code-mapped M-ary phase-shift-keying (PSK) modulation and quadratic-amplitude modulation (QAM), is analytically derived. Moreover, MO-STBCs can also easily be combined with existing linear O-STBC decoders specifically designed for the time-selective channel, yielding significant performance improvement over conventionally constructed and decoded O-STBCs.