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In the Multiple Input Multiple Output (MIMO) systems, the receiver performance is greatly affected by Antenna Gain Imbalance (AGI). This paper proposes an novel AGI detection algorithm based on the Least Square (LS) channel estimation. The AGI parameter is accurately obtained after eliminating the influence of noise from the channel through the long-term statistics. Moreover, a compensation algorithm...
Performance of next generation OFDM/OFDMA based Distributed Cellular Network (ODCN) where no cooperation based interference management schemes are used, is dependent on four major factors: 1) spectrum reuse factor, 2) number of sectors per site, 3) number of relay station per site and 4) modulation and coding efficiency achievable through link adaptation. The combined effect of these factors on the...
We develop a general model based on random coding bounds to explain and predict the coding performance of various type-I and type-II hybrid automatic repeat request (HARQ) schemes based on the bit-interleaved coded modulation (BICM) in 3GPP HSPA. We explore how the intrinsic properties of BICM interact with various transmitter-side (e.g., whether to use the same bit mapping for retransmission) and...
In this paper we propose a novel hybrid multicarrier architecture for wireless LAN (WLAN) applications. We refer to this architecture as hybrid filtered multitone (HFMT). Depending on the experienced channel condition, H-FMT switches between short orthogonal FMT (SO-FMT) modulation, and adaptive orthogonal frequency division multiplexing (A-OFDM). Extensive numerical results show that H-FMT could...
With the ever-increasing proliferation of air interfaces that coexist in the same operating area, advanced Radio Resource Management is crucial to take advantage of the available system resources. In this paper, we consider a downlink multi-class heterogeneous network where cells include two co-localized Radio Access Technologies (RAT): WiMAX [1] and UMTS [2]. We propose a Centralised Access Control...
In this work we study a recently proposed multiple-input multiple-output (MIMO) system called the Layered Steered Space-Time Codes (LSSTC) that combines the benefits of vertical Bell Labs space-time (VBLAST) scheme, space-time block codes (STBC) and beamforming. The aim of this research is to investigate the analytical error performance of single user LSSTC. In addition, the tradeoff between several...
Despite the very substantial body of research on the performance analysis of cooperative relay systems, most studies focus on either the symbol error ratio (SER) or outage behavior. This paper analyzes the asymptotic average packet error rate (PER) of the packet cooperative relay system for both AF (Amplify-and-Forward) and DF (Decode-and-Forward) schemes in the high signal-to-noise ratio (SNR) region,...
We study the physical layer design of a distributed time-division multiple access (TDMA) protocol for wireless body area networks (WBAN). The distributed TDMA scheme is derived from a bio-inspired algorithm known as Pulse-Coupled Oscillator (PCO), in which each node in the network updates its state based on its knowledge of the neighborhood. ON-OFF ultra wide band (UWB) modulation is used by the sensors...
In this paper we focus on compressive sampling (CS) based ultra wideband (UWB) differential detection. We formulate an optimization problem to jointly recover the sparse received UWB signals as well as the differentially encoded data symbol. We utilize an alternating direction method of multipliers (ADMoM) to solve this joint optimization problem. Our proposed joint recovery method outperforms the...
Multi-carrier modulation and especially CP-OFDM is widely used nowadays in several radio communications. However, FBMC is a potential alternative to CP-OFDM since it does not require cyclic prefix, and thus, it has a higher spectral efficiency. One of the characteristics of FBMC is that the received data are accompanied by a two dimensional inter-symbol interference term (2D ISI), which complicates...
In this paper the performance of multiple-input multiple-output (MIMO) system in the UTRAN Long Term Evolution (LTE) standard is evaluated by means of ergodic system capacity in low (3 km/h), medium (30 km/h) and high (120 km/h) mobility scenarios. The impact of adaptive modulation as well as Hybrid ARQ (HARQ) with Chase Combining to the distribution of effective SINR is established analytically and...
In this paper we consider an IEEE 802.15.4-based Wireless Body Area Network, where wearable sensor devices are distributed on a body and have to send the measured data to a coordinator. The Carrier Sense Multiple Access with Collision Avoidance algorithm defined by the standard is used as Medium Access Control protocol, whereas different modulation schemes are assumed to be available at the physical...
Being sensitive to carrier frequency offset (CFO) is known to be one of the main drawbacks of multicarrier systems. In this paper, the effects of CFO on a filter bank based multicarrier system (FBMC) in a multipath fading channel are discussed, where an ideal root-raised cosine (RRC) filter with roll-off factor 1 is used as the prototype filter which enables analytical derivations of the interference...
In this paper, we analyze the ergodic capacity (per unit bandwidth) and Average symbol error probability (ASEP) of an incremental relaying protocol used in conjunction with opportunistic relaying and consider a non-regenerative wireless relay network with Rayleigh fading channels. We consider a selection combining technique at the destination in order to combine the two signals, one from the direct...
One way of fully exploiting the channel capacity in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is to deploy precoding vectors derived from SVD to form parallel data pipes. Optimal precoding requires accurate channel state information for each OFDM subcarrier. This paper proposes a limited channel decomposition architecture by using an interpolation...
Estimation of the variance of AWGN is important to the initialization of iterative decoder, such as turbo code and LDPC code. Hence this paper puts forward a low-complexity and effective blind Gaussian variance estimator for MPSK and MQAM. The algorithm is derived from empirical characteristic function and provides a good un-biased estimation despite the knowledge of modulation type, as is proved...
Adaptive modulation and power allocation schemes have been widely used in multiple-input multiple-output (MIMO) systems to enhance spectral efficiency while maintaining bit error ratio (BER) to a target level. We derive the spectral efficiency of orthogonal space-time block codes (OSTBC) that can be achieved by applying adaptive modulation and power allocation. Compared to non-adaptive power scheme,...
Medium Access Control (MAC) protocols with transmission power control, rate control and modulation control have been proposed to improve the performance of ad hoc networks and provisioning of differentiated service in wireless networks. However, its effectiveness is reduced in the presence of strong noise over the wireless channels. It is further aggravated in wireless mesh networks (WMN) due to the...
In this paper, we consider a simple loading algorithm for Orthogonal Frequency Division Multiplexing systems in WLAN for signal spectrum optimization. The algorithm is based on the margin adaptive loading criterion and its performance over 5GHz indoor wireless channels.
Jitter is the limiting effect for high speed analog-to-digital converters with high resolution and wide digitization bandwidth, which are required in receivers in order to support high data rates. The rapid development of digital wireless system has led to a need of high resolution and high speed analog to digital converter. The performance of a data converter is dependent upon the accuracy and stability...
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