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Modern wireless systems deal with the adverse and unpredictable channel conditions using two main transmission schemes considered as complimentary: adaptive modulation and coding (AMC) and hybrid ARQ (HARQ). In this work we use the effective capacity as the performance measure to evaluate different design options. We thus show how to calculate this performance measure under independent, identically...
An interference alignment (IA) algorithm for uplink coordinated multi-point (CoMP) is proposed. For the design of precoder at the transmitter, the unselfish per-user signal-to-leakage-and-noise ratio (SLNR) criterion is used. On the other hand, the per-user signal-to-interference-and-noise-ratio (SINR) criterion is adopted to determine the decoder of the receiver. The proposed algorithm does not rely...
In this paper, we will analyze how different amount of receiver side information (RSI) available at the receivers of a broadcast channel will affect the overall network throughput. Two transmission schemes, namely random linear network coding (RLNC) and round robin scheduling (RRS), are considered. Taking into account the differing amount of RSI available at each receiver, closed-form expressions...
This paper deals with the network spectral efficiency/capacity analysis of multiple-input multiple-output (MIMO) ad hoc network with K simultaneous communicating transceiver pairs in two scenarios; quantized beamforming for achieving finite rate feedback and imperfect channel state information at the transmitter (CSIT). In the quantized beam forming, each receiver chooses the best beamforming vector...
In this paper, we propose a limited feedback scheme to minimize the outage probability for a wireless cooperative decode-and-forward network. Specifically, based on the instantaneous conditions of the source-destination and relay-destination channels, the destination will allocate the transmission time of the source and relay and feed back the allocation results to the source. Both full, or infinite-rate,...
In this paper, an energy efficient adaptive modulation scheme is proposed for a wireless cognitive radio ad hoc network, where each node is equipped with cognitive radio and the network is an OFDMA system operating on time slots. In each slot, the users with new traffic demand will sense the spectrum and locate the available subcarrier set. Then they choose subcarriers with favorable channel condition...
By exploiting properties of the wireless medium, network coding may provide even larger throughput increases for wireless networks than possible for wired networks. In particular, simultaneously transmitted signals are seen as noisy linear combinations at the antennas of receivers. It is thus quite tempting to use the physical layer to directly perform network coding "on the air". However,...
Decoding algorithm complexity influences the application of low-density parity-check (LDPC) codes. This article investigated the Belief-Propagation and improved decode algorithms for a subclass of binary LDPC that can be encoded linearly. Through the comparison of decoding performance, a low complexity one with good performance is preferred. It is shown that the incorporation of LDPC coding techniques...
In this paper, we concentrate on opportunistic scheduling for multicast information. We pose the problem as a multicast throughput optimization problem. As a solution we present how one can jointly utilize fixed-rate and rateless erasure coding along with simple rate adaptation techniques in order to achieve the optimal multicast throughput per user. We first investigate the performance of the proposed...
Li and Xia have recently investigated the design of space-time codes that achieve full spatial diversity for asynchronous cooperative communications. They show that certain of the binary space-time trellis codes derived from the Hammons-El Gamal stacking construction are delay tolerant and can be used in the multilevel code constructions by Lu and Kumar to produce delay tolerant space-time codes for...
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...
This paper studies efficient complex valued matrix manipulations for multi-user STBC-MIMO decoding. A novel method called Alamouti blockwise analytical matrix inversion (ABAMI) is proposed for the inversion of large complex matrices that are based on Alamouti sub-blocks. Another method using a variant of Givens rotation is proposed for fast QR decomposition of this kind of matrices. Our solutions...
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