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Combining coding, modulation, transmit and receive diversity, and validly increases the anti-noise performance in fading channels, OSTBC (orthogonal space-time block codes) is a new channel coding technology accompanying with the extensive application of wireless communication. Based on typical channel model of the OSTBC in MIMO (multiple-in, multiple-out) wireless communication channels, a general...
Precoding is an efficient approach to obtain high channel capacities and high quality in multiple-input-multiple-output systems and draws much attention in recent researches. In the codebook-based precoding systems, the tradeoff between performance and feedback overhead should be considered. In this paper, a novel version of the Linde-Buzo-Gray (LBG) algorithm is first utilized in the codebook design...
Recent results have shown that it is possible to obtain the diversity advantages promised by multiple transmit/receive antennas through the use of collaboration. Collaboration entails having a source wishing to communicate to a destination with the help of a relay. Two-phase protocols have been developed to provide collaboration in wireless networks. Previous work has assumed a fixed amount of time...
This paper proposes a new systematic design framework called DBOASTBC-OFDM for wideband wireless communications in a MIMO (multiple-input multiple-output) system, which is developed from combining the orthogonal frequency division multiplexing (OFDM) with the diagonal block orthogonal algebraic space-time block code (DBOASTBC) and belongs a kind of MIMO-OFDM multicarrier systems. The methods of encoding...
In this paper, we propose a robust STBC transmission scheme to combat the timing synchronization errors over frequency-selective multiple-access channels. First, the equivalent channel model in the presence of timing synchronization errors is derived and we find that the synchronization errors result in an equivalent channel model with larger number of correlated channel taps. Based on this correlated...
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H), which is required to operate under high mobility conditions resulting in significant Inter-carrier Interference (ICI). To mitigate ICI, several cancellation schemes have been proposed but they require reliable channel information at the receiver which is quite challenging...
Some communication applications, like multimedia, deliver data of different importance classes allowing unequal error protection (UEP) levels. In this paper, a multiple-input multiple-output (MIMO) system using orthogonal frequency division multiplexing (OFDM) is considered with a new UEP bit-loading algorithm based on the non-UEP algorithm by Chow, Cioffi, and Bingham. In the proposed bit-loading...
A new construction of a full-diversity full-rate space-time block code (FDFR-STBC) is presented in this paper. The design is for 2 transmit antennas and 2 time slots. The code outperforms the previous FDFR-STBC codes in [3], [4], [5], [6] for 1 receive antenna. We reduce the decoding complexity by exploiting the algebraic structure of the code and using the hybrid maximum-likelihood interference cancellation...
In this paper, we study bandwidth management of a wireless/optical based access/metro network in support of voice and data services. For voice services, we use a finite state Markov Chain to estimate the blocking probability of voice circuits over an Adaptive modulation and coding wireless channel, as a function of the channel parameters. For data services, we evaluate a rate matching and a buffer...
This paper proposes a new space-frequency (SF) code construction scheme that can fully exploit both spatial and frequency diversities while providing great coding advantage and maintaining high bandwidth efficiency for MIMO-OFDM system operating in frequency-selective channels. The proposed SF code construction method is based on a class of trellis codes, where the trellis branches are labeled with...
Effects of improved channel estimation are studied for a proposed IEEE 802.11n OFDM MIMO system. Three channel estimation methods are considered: maximum likelihood (ML), time-domain truncation (TDT) and model-based (MB). TDT and MB are particularly useful when the channel delay spread is short. For an MMSE receiver, MB shows a 1-2.5 dB improvement over ML on the packet error rate performance for...
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