In this paper we propose couple power allocation strategies for layered video services delivery over evolved Multimedia Multicast/Broadcast Service (eMBMS) networks. The proposed allocations aim at reducing the power consumption of the eNodeB (eNB) and improving the user quality of experience characterizing the delivered eMBMS flows. We consider multiple challenging scenarios which differ by: (i) the number of eNBs transmitting the same service set, and (ii) how services are delivered. In particular, we consider scenarios where services can be delivered by resorting to the Random Network Coding principle or not. We compare the proposed resource allocation models to a strategy which equally shares the transmission power budget among layers of the delivered service. Analytical results show that the proposed resource allocation strategies are characterized by a transmission power which is on average 13% smaller than the considered alternative. In addition, the optimized resource allocation can deliver each layered video service over a geographical area which is up to 25% greater than that associated to the considered alternative.

Random Network Coding (RNC) has recently been investigated as a promising solution for reliable multimedia delivery over wireless networks. RNC possess the potential for flexible and adaptive matching of packet-level error resilience to both video content importance and variable wireless channel conditions. As the demand for massive multimedia delivery over fourth generation wireless cellular standards such as Long-Term Evolution (LTE)/LTE-Advanced (LTE-A) increases, novel video-aware transmission techniques are needed. In this paper, we investigate RNC as one such promising technique, building upon our recent work on RNC integration within the LTE/LTE-A Radio Access Network at the Multiple Access Control (MAC) layer (MAC-RNC). The paper argues that the proposed MAC-RNC solution provides fundamentally new set of opportunities for dynamic collaborative transmission, content awareness, resource allocation and unequal error protection (UEP) necessary for efficient wireless multimedia delivery in LTE/LTE-A.

This paper presents an innovative spectrum sensing scheme for Orthogonal Frequency Division Multiplexing (OFDM) signals based on enhancing the performance of the popular autocorrelation detectors (AD) using non-linear image processing methods. These methods improve the detection accuracy of the AD under particular false-alarm constraints. The proposed scheme is used in the detection of two OFDM systems, Long Term Evolution (LTE) and DVB terrestrial digital TV (DVB-T) under low signal to noise ratio (SNR) channel conditions. Results obtained show significant improvement in correct signals detection/classification up to 18% and 48% at a false-alarm of 5% and low SNR conditions equal to -18dB, using the combined AD and image processing scheme for the detection of LTE and DVB-T signals, respectively.

In this paper, we propose a novel advanced multirate design for evolved Multimedia Multicast/Broadcast Service (eMBMS) in fourth generation (4G) Long-Term Evolution (LTE)/LTE-Advanced (LTE-A) networks. The proposed design provides: i) reliability, based on random network coded (RNC) transmission, and ii) efficiency, obtained by optimized rate allocation across multi-rate RNC streams. The paper provides an in-depth description of the system realization and demonstrates the feasibility of the proposed eMBMS design using both analytical and simulation results. The system performance is compared with popular multi-rate multicast approaches in a realistic simulated LTE/LTE-A environment.

Mobile video services are becoming a dominant traffic category in emerging fourth generation (4G) cellular networks such as the 3GPP Long-Term Evolution (LTE) and LTE-Advanced (LTE-A). In particular, mobile video broadcasting services such as 3GPP evolved Multimedia Multicast/Broadcast Service (eMBMS) will require considerable resources for highquality video service delivery with high coverage probability. Faced with the challenge of bandwidth and energy efficient eMBMS provisioning over LTE/LTE-A, in this paper, we develop simple analytical tools for evaluation of average service data rates, bandwidth and energy-consumption requirements in different eMBMS LTE/LTE-A service configurations. Moreover, we introduce and evaluate novel bandwidth and energy performance measures defined per unit of service with the goal of comparing the service delivery efficiency of different LTE/LTE-A configurations. The results in the paper focus on eMBMS provisioning over two macro-cellular LTE/LTE-A configurations in 3GPP: i) a single frequency network eMBMS, and ii) a single-cell eMBMS.

In this paper, we propose integration of random network coding (R-NC) sublayer at the Radio Link Control/Multiple Access Control (RLC/MAC) layer boundary within the 3GPP Long Term Evolution (LTE) Radio Access Network (RAN) protocol stack. R-NC is introduced as a simple alternative to the MAC/Physical Layer (PHY) Hybrid Automatic Repeat reQuest (HARQ) protocol for reliable RLC protocol data unit (PDU) transmission over the radio interface between the base station (eNB) and the mobile user equipment (UE). To evaluate and compare the performance of the R-NC-based solution against the standardized HARQ-based one, we develop a novel link-level simulator which combines packet-level Finite-State Markov Chain (FSMC) channel models and existing LTE PHY layer simulators. Using this simulator, the R-NC and the HARQ-based alternatives are compared with respect to continuous transmission of RLC PDUs between the eNB and the UE over a direct radio link or via relay-node (RN) assisted multi-hop connection. The focus of this technical study is on the possible throughput, energy, delay and implementation complexity reduction benefits of the proposed R-NC-based solution over the HARQ-based protocol.

Random Network Coding (RNC) has recently been investigated as a promising solution for reliable multimedia delivery over wireless networks. Based on Random Linear Codes (RLC) and their systematic, sparse and Unequal Error Protection (UEP) extensions, RNC possess the potential for flexible and adaptive matching of packet-level error resilience to both video content importance and variable wireless channel conditions. As the demand for massive multimedia delivery over 4G wireless cellular standards such as LTE/LTE-A increases, novel video-aware transmission techniques are needed. In this paper, we investigate RNC as one such promising technique. In contrast to the normal use of RNC as an application layer technique (AL-RNC), this paper focuses on RNC integration within the MAC layer (MAC-RNC) of the LTE/LTE-A Radio Access Network (RAN). The paper argues that the proposed MAC-RNC solution could successfully replace the current MAC layer HARQ error resilience mechanism while providing new opportunities for content awareness, resource allocation and UEP which are fundamental for efficient wireless multimedia delivery.

Recent trends witness the shift of the 3GPP Long Term Evolution - Advanced (LTE-A) radio access network (RAN) architecture from a traditional macro-cellular layout towards smaller base stations moving closer to end users. The evolved LTE-A RAN offers rich environment for multi-point and multi-hop cooperation and coordination resulting in increased capacity and more predictable channel conditions between heterogeneous base stations and end users. While these opportunities are recently well investigated at the physical layer through various cooperative multi-point (CoMP) schemes, upper layer protocols preserve the design proposed for macro-cellular single-hop data delivery. In this paper, we address this issue by proposing and investigating in detail a cooperative RAN-wide MAC layer protocol based on random network coding (RNC) that is designed specifically for reliable and flexible data delivery over the evolved LTE-A RAN. The proposed RNC-based MAC protocol (MAC-RNC) is evaluated and compared with the existing HARQ-based (MAC-HARQ) protocol in various LTE-A RAN layouts using a customized packet-based link-level simulator based on Finite-State Markov Chain (FSMC) channel models. Our results show that the MAC-RNC protocol introduces simplicity and flexibility required for future LTE-A RANs, while preserving or improving the performance of the MAC-HARQ protocol in traditional single-point single-hop macro-cellular scenarios.

In long-term-evolution-advanced (LTE-advanced), heterogeneous deployments of relays, femtocells and conventional macrocells are expected to provide coverage extension and throughput enhancement, while significantly lowering the energy consumption and total-cost-of-ownership (TCO) in cellular networks. This study presents a methodology for estimating the total energy consumption, taking into account the total operational power and embodied energy, and TCO of wireless cellular networks, and in particular provides a means to compare homogeneous and heterogeneous network (HetNets) deployments. The authors introduce realistic energy models and energy metrics based on information available from mobile-network operators (MNOs) and base stations manufacturers. Additionally, up-to-date operational and capital expenditure (OPEX and CAPEX) models are used to calculate TCO of candidate networks. The authors evaluate two scenarios for HetNets, namely a joint macro-relay network and a joint macro–femtocell network, with different relay and femtocell deployments densities. The results obtained show that compared to macro-centric networks, joint macro-relay networks are both energy and cost efficient, whereas joint macro–femtocell networks reduce the networks TCO at the expense of increased energy-consumption. Finally, it is observed that energy and cost gains are highly sensitive to the OPEX model adopted.

This paper addresses the problem of wireless delivery of a captured scene from two cameras, which do not communicate with each other, to a central point for joint decoding. We exploit correlation among two camera views using distributed source coding and use complete complementary (CC) data spreading to combat multiple access interference and noise even when the transmitters are de-synchronized. Our distributed source coding scheme is based on uniform scalar quantization in the DCT domain and non-asymmetric Slepian-Wolf coding via turbo codes. The non-asymmetric Slepian-Wolf scheme enables efficient trade-off between the transmission rates of the two cameras. Simulation results indicate that the proposed system outperforms significantly two independently JPEG-encoded streams at low transmission rates.

We propose a new technique, compress-spread forward (CSF), for high-performance wireless streaming from two base stations in parallel. CSF uses multiterminal source coding for efficient source compression and complete complementary sequences for error-free multiple access and synchronization. Our practical design shows significant performance gains due to spatial diversity and distributed source coding.

Data streaming from multiple base stations to a client is recognized as a robust technique for multimedia streaming. However the resulting transmission in parallel over wireless channels poses serious challenges, especially multiple access interference, multipath fading, noise effects and synchronization. Spread spectrum techniques seem the obvious choice to mitigate these effects, but at the cost of increased bandwidth requirements. This paper proposes a solution that exploits complete complementary spectrum spreading and data compression techniques jointly to resolve the communication challenges whilst ensuring efficient use of spectrum and acceptable bit error rate. Our proposed spreading scheme reduces the required transmission bandwidth by exploiting correlation among information present at multiple base stations. Results obtained show 1.75 Mchip/sec (or 25%) reduction in transmission rate, with only up to 6 dB loss in frequency-selective channel compared to a straightforward solution based solely on complete complementary spectrum spreading.

This paper addresses a data-hiding problem where a source image needs to be hidden into another host image. We consider both cases when the decoder has access to the host image (non-blind data-hiding), and when the decoder does not (blind data-hiding). Our proposed solution combines complete complementary (CC) spreading sequences and nested scalar quantization (NSQ). To enhance security, the source image is encrypted prior to embedding. Our simulation results, for both non-blind and blind data-hiding, with AWGN attacks show competitive results. Indeed, for blind data-hiding, our design outperforms the traditional NSQ system by 8 dB.

We present a multiple-input-multiple-output (MIMO) code-division-multiple-access (CDMA) communication system based on complete complementary (CC) codes (CC-CDMA) in a time-dispersive (i.e. frequency-selective fading) channel. This system utilizes a novel combination, which consists of orthogonal CC codes for data spreading and a suitably designed multiuser-detector (MUD) algorithm, in order to enhance the current 3rd generation (3G) mobile systems. The simulation results for the CC-CDMA system, obtained in a frequency-selective fading channel, reveal significant improvement in bit-error-rate (BER) performance, and consequently the achieved high data rates (HDR) compared with a conventional Walsh codes based MIMO CDMA (Walsh-CDMA) system.

Suitable techniques for high-speed downlink packet access (HSDPA) services, using wideband code division multiple access (WCDMA), are currently being considered by the third generation partnership project (3GPP). One of the systems currently under consideration is a space-time coding (STC) architecture using the vertical-bell-labs-layered-space-time (V-BLAST) system on the downlink-shared channel (DSCH), which will allow simultaneous transmissions over multiple channels destined for a single user. Although link level results for flat fading channels indicate significant performance advantages over the conventional single antenna systems, it is less successful for frequency-selective fading. Corresponding methods of design implementation are also being developed using techniques such as system-on-a-chip (SoC), digital signal processors (DSPs), and field program gate arrays (FPGA). In this paper, we present a performance comparison for both fixed and floating point DSP implementations for the proposed V-BLAST system.