BACKGROUND:Inflammation is critical to the pathogenesis and progression of cancer, with a high neutrophil-lymphocyte ratio (NLR) associated with poor prognosis. The utility of studying NLR in early clinical trials is unknown.METHODS:This retrospective study evaluated 1300 patients treated in phase 1 clinical trials between July 2004 and February 2014 at the Royal Marsden Hospital (RMH), UK. Data were collected on patient characteristics and baseline laboratory parameters.RESULTS:The test cohort recruited 300 patients; 53% were female, 35% ECOG 0 and 64% ECOG 1. RMH score was 0-1 in 66% and 2-3 in 34%. The median NLR was 3.08 (IQR 2.06-4.49). Median OS for the NLR quartiles was 10.5 months for quartile-1, 10.3 months for quartile-2, 7.9 months for quartile-3 and 6.5 months for quartile-4 (P<0.0001). Univariate analysis identified RMH score (HR=0.55, P<0.0001), ECOG (HR=0.62, P=0.002) and neutrophils (HR=0.65, P=0.003) to be associated with OS. In multivariate analysis, adjusting for RMH score, ECOG, neutrophils and tumour type, NLR remained significantly associated with OS (P=0.002), with no association with therapeutic steroid use. These results were validated in a further 1000 cancer patients. In the validation cohort, NLR was able to discriminate for OS (P=0.004), as was the RMH score. This was further improved on in the RMH score+NLR50 and RMH score+Log10NLR models, with an optimal NLR cutoff of 3.0.CONCLUSIONS:NLR is a validated independent prognostic factor for OS in patients treated in phase 1 trials. Combining the NLR with the RMH score improves the discriminating ability for OS.

The IEEE 802.16 has a reservation based, centralized approach for allocating bandwidth on the upstream channel. In this paper, we proposed a queue length based weighted round robin (QL-WRR) scheduling algorithm to assess the efficient usage of upstream bandwidth of the IEEE 802.16 MAC protocol. This scheduling algorithm provides fairness. In QL-WRR scheduling algorithm, the scheduler takes the arrival rates of packets at the SS’s into account. A mathematical model is developed to determine the probability transmission by an SS, and probability of collision in a minislot. These parameters are used to obtain the uplink performance. The proposed mathematical model allows the dynamic variation of ratio between contention and data minislots according to the network load to improve the uplink utilization.

With increasing demand for higher computational speed & emerging micro-systems, thermal management poses serious challenge for efficient cooling. Among these liquid cooling, using micro channels has gained significant attention using single phase flow. These micro channel heat sinks combine the attributes of high material compatibility, high surface area per unit volume ratios & large potential heat transfer performance with fabrication Process. The various geometrical parameters affect the performance of the system. Various design configurations have been prepared & evaluated on the response parameters such as thermal resistance & pumping power. In this study, Taguchi Arrays are used to analyze the effect of various geometrical parameters & response parameters on micro channel performance. In addition, channel wall and base thickness along with type of material affecting the performance is also analyzed. Results show that channel width, height and substrate thickness at the base are the prime factors of concern. In addition, interactive effect of wall and base thickness is also found to affect the performance significantly & their low values for optimum performance is recommended.

A novel high speed OFDM based underwater modem with phase coherent modulation has been proposed for video communications. The key to achieve this objective is passband sampling, which enables us to perform coherent detection with precise control over the carrier phase by using digital carriers. Currently commercially available long-range underwater mo-dems provide a maximum data rate of 38 kbps over a 1 km deep water vertical path [1]. These data rates are not sufficient for real-time video communication. To provide real-time video trans-mission we employ a high bandwidth efficient modulation scheme such as OFDM. We have designed a 64 kbps acoustic modem which can transmit QCIF video at one frame per second for 1 km distance. Simulation studies are carried out to validate the designed system.

This paper discuss the channel estimation and data detection for Long Term Evolution (LTE) air interface over time varying frequency selective channels using a modified superimposed training (SIT) sequence method. This method can be significantly improved the accuracy by exploiting time and frequency correlations between the channel frequency response coefficients (coherence time and coherence bandwidth). In SIT based channel estimation scheme, training sequence is arithmetically added to the data sequence at a desired power allocation ratio at the transmitter. At the receiver the channel estimation is done by using the same SIT sequence with iterative process. The simulation results shows that the proposed method is superior than the conventional channel estimation method (2-D pilot based method) and previous proposed SIT based method for higher order modulation and high mobility cases.

A cross-correlation function (CCF) based timing synchronization algorithm of low complexity, applicable for single-band transmission is presented. Novelty of the synchronizer lies in utilization of specific preamble structure of the Multi-band OFDM frame format. This threshold based algorithm also takes care of the fact that stronger multipath components frequently appear on the later clusters. Performance of the algorithm is measured in terms of mean-squared-error and synchronization probability. Performance is compared with another single-band based timing algorithm by Yak et al. [2]. The probability of correct detection is analyzed mathematically to verify the experimental results.

Speech is a non-stationary signal. The non-stationarity of the speech arises from emotional variations, speaker and environment variations. Almost all of the speech coding standards available today rely on stationary models for the modelling of time varying parameters of the speech generation model which affects the perceptional quality of the coded speech. Physically non-stationarity can be interpreted as the manifestation of the time varying nature of the speech generation source-the vocal tract. The vocal tract can be roughly modelled as a Autoregressive (AR) filter(all pole model). The time varying nature of the vocal tract corresponds to the time-varying AR parameters. The time varying AR parameters are expressed as the sum of Haar wavelets. Thus the estimation of time varying AR parameters boils down to that of finding the time invariant coefficients of the Haar wavelet basis functions. Here we propose a variable bit rate codec which attempts to bring in the non stationary modelling of the time varying AR parameters of the speech. Further long term prediction(LTP) and AbS method can be incorporated to develop a codec using this short term prediction method. It can be seen that the Haar wavelet based speech coding method over-performs the traditional method.

Reducing Carbon emissions in general in ICT from the present 3 percent and in particular in Mobile communications has been of a serious concern. In the next generation cellular technologies like LTE, base stations are very energy hungry, as they need to provide high spectral efficiency and wide coverage. Given that there is no cooling required for modern systems, the transmit power in a typical link is the most important constituent in a base station. This is mainly due to its power amplifiers and also due to energy loss in the power supply. LTE uses OFDM in downlink, which requires huge complex computations, and the power consumption of the transceiver hardware. With the latest CMOS technology, a two-fold reduction in the operating voltage from 130 nm technology to 22 nm technology, results in a four-fold reductions in the transceiver power consumption. With the LTE technology poised to take off, it is interesting to see the energy consumption assessment of LTE considering the projection of technology and exploiting the different mode of operation and the methods of reducing energy consumption. This paper discusses about the various possibilities and makes a practical assessment of a possible green form of LTE.

This study pertains to the use of superimposed training (ST) in closed-loop multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. A novel method consisting of a technique to refine the channel estimate at the transmitter in an ST-based closed-loop MIMO-OFDM system is proposed. The estimate is refined at the transmitter by making use of the previous data that was transmitted. This significantly reduces the data interference in the channel estimate and hence improves performance. The mean squared estimation error (MSEE) of the refined channel estimate is mathematically analysed and it is shown that in the limit, the accuracy of the refined channel estimate is identical to the pilot-assisted case with the additional advantage of the bandwidth efficiency inherent in ST-based systems. Two factors in general affect all transmitter side techniques that make use of the fed back channel coefficients. One is the quantisation error affecting the channel estimate. The other is the channel variations that may render the fed back channel coefficients outdated for further use. The effect of these factors on the proposed refined channel estimation scheme is discussed in detail. Simulation results are presented in terms of the MSEE and the bit error rate performance demonstrating the usefulness of the proposed scheme.

A closed form expression of bit-error-rate (BER) has immense importance for insightful understanding on the performance of a communication system. In this paper we provide the BER analysis of a convolution coded MB-OFDM Ultra-Wideband (UWB) system that captures the log-normal fading statistics of UWB channels and also considers the estimation error variances of timing and carrier frequency offset (CFO) estimation by our already published synchronizers(1) ATS (Sen et al., 2008 [1,2]) and MBAFS (Sen et al., 2008 [3,4]) respectively. By invoking the moment generating function (MGF) for log-normal fading statistics and using the Gauss-Hermite quadrature integration the average BER for rate R, coded QPSK modulation with ATS and MBAFS synchronizers and channel estimation by least square (LS) method is obtained. We compare the analytical result with simulation results in highest delay spread UWB channel model CM4 and validate the consistency of our theoretical analysis. (C) 2010 Elsevier Inc. All rights reserved.

INTRODUCTION:The genetic make-up of malaria parasite is potent for understanding the parasite virulence, designing antimalarial vaccine and evaluating the impact of malaria control measures. There is a paucity of information on genetic structure of Plasmodium falciparum in Jharkhand, India where malaria is rampant and this study aimed to establish molecular characterization of P. falciparum field isolates from Jharkhand measured with two highly polymorphic genetic markers, i.e. the merozoite surface proteins (MSPs) 1 and 2.METHODS:The genetic diversity of P. falciparum population from low transmission area, Ranchi, Bokaro and Hazaribagh and highly malarious area, Latehar and Palamau districts of Jharkhand were evaluated by polymerase chain reaction-sequencing analyzing msp-1 and msp-2 genes to explore the genetic structure of parasite from this understudied region.RESULTS:A total of 134 P. falciparum isolates were analyzed by polymorphic regions of msp-1 and msp-2 and classified according to prevalence of allelic families. The majority of patients from all the five sites had mean monoclonal infections of 67·1 and 60·4% of P. falciparum for msp-1 and msp-2, respectively, whereas, mean multiple genotypes of 32·8 and 39·5% for msp-1 and msp-2, respectively. Interestingly, we observed higher multiclonal infection in low transmission area as compared to highly malarious area in the case of msp-1 genotypes, whereas in msp-2 higher multiclonal infection was observed in highly malarious area compared to low transmission area. The overall multiplicities of infection of msp-1 and msp-2 were 1·38 and 1·39, respectively.CONCLUSION:This is the first report on molecular characterization of P. falciparum field isolates from Jharkhand. The genetic diversity and allelic distribution found in this study is somewhat similar to other reports from India and Southeast Asian countries. However, P. falciparum infection can be highly complex and diverse in these disease-endemic regions of Jharkhand, suggesting continual genetic mixing that could have significant implications for the use of antimalarial drugs and vaccines.

Energy consumption is an issue in general in information and communication technologies (ICT), but also cellular communications in particular. Base station sites are the main energy consumers in a mobile network. Their energy consumption significantly contributes to green house gas (Co2) emissions. It has been found that digital baseband is the main contributor to dynamic part of the power consumption in new base station deployments due to its explosive computational complexity. Hence, the implementations of baseband subsystem need to be energy efficient in advanced systems and thus to reduce Co2 foot print and save on energy costs. In this paper, we have presented an approach for evaluating energy efficiency metrics for any signal processing algorithm on TI's DSP and Xilinx FPGA. This evaluation of energy metrics is very much required to characterize the implementations and for quantifying the gains achieved from any energy efficient strategy. In addition, we showed that reducing execution cycles taken by signal processing algorithm effectively reduces its dynamic power consumption. As an example, FFT/IFFT algorithm, one of the critical block in OFDMA systems is considered for energy analysis.

In an library based waveform (WF) development for software defined radios, high-level performance estimation models of implementations are beneficial for converging quickly to an optimal mapping of a WF-description to a hardware platform. A model that estimates the changes in performance, e.g. bit error rate (BER), due to the configuration-parameters, e.g. input datawidth, in implementations is helpful for evaluating a mapping decision with tool assistance. Using FFT as an example, this paper introduces a general method to estimate the BER variations due to the finite word length (FWL) effects in implementations by modeling the error as a noise. Quantitatively, the root mean square error due to the FWL effects has been linked to the noise power spectral density (PSD). This leads to the modification of theoretical expressions based on the PSD of the channel noise to estimate the BER. The accuracy of the proposed model is extensively verified using 10 commercial implementations of FFT in 15 different configurations. Additionally, architectures of various FFT implementations have been analyzed and a high-level estimate of latency is provided. Simulation results demonstrate the high accuracy of the proposed models.

This article deals with a new energy based adaptive timing synchronization scheme (ATS) which estimates the symbol timing information within two (2) OFDM symbols and updates the information with different frequency bands (adaptive in sense) in a multi-band orthogonal frequency division multiplexing (MB-OFDM) based system. The new approach provides significant improvement in system performance for high delay spread ultra-wideband (UWB) channel model (CM) environments where fast and low-complexity timing synchronization is a critical issue. This paper also addresses a crucial aspect of UWB channel which is frequency dependent delay characteristics. This effect contributes to different dispersion and timing shift of an UWB signal for different frequency bands. In this work, the wideband channel delay characteristics are studied and delay parameters are found considerably different over frequency bands 3.1–4.6 GHz. Based on this observation, the ATS which estimates and maintains the timing delays of each band separately is presented. The performance of ATS algorithm is measured by mean-squared error (MSE), synchronization probability, signal to interference ratio (SIR) reduction due to synchronization errors and bit error rate (BER) through the computer simulation for several UWB CM environments CM2–CM4. Each of these UWB CMs is simulated for 100,000 noisy channel realizations for both coded and uncoded MB-OFDM system. It is shown that ATS gives signal-to-noise ratio (SNR) improvement of 1.1 dB at BER of 1 × 10−3, 1.2 dB at BER of 2 × 10−4, and 0.7 dB at BER of 2 × 10−4 for CM4, CM3, and CM2 respectively for coded MB-OFDM system over a non-adaptive synchronization scheme [Yak et al., Proceedings of IEEE PIMRC, Berlin, Germany, vol 1, pp 471–475, September 11–14, 2005].

The correct formulation of the likelihood ratio test (LRT)-based detection schemes for a target in the presence of clutter needs a faithful and mathematically tractable clutter model. The state-of-art detection methods usually assume that the land and sea clutter in whose presence a target signal to be detected as K-distributed form of non-Gaussian clutter and uses an LRT detector obtained for the same. However, the macroscopic phenomena of clutter generation in a search radar and also the detailed studies on the measured clutter data show a significant texture fluctuation caused by the continuous antenna scanning motion. Incorporation of the scanning effect in the clutter model introduces challenges in modelling the varying texture and formulating a suitable detection scheme. Here the authors propose a clutter model for such scanning radar applications taking the effect of scanning on the clutter correlation into consideration. A method of fitting the proposed model to measured data and a method of simulating the clutter as per the proposed model are also presented. The proposed model is found to be attractive for an LRT detector design. Further in this study, the proposed clutter model is also validated through a real experimental data which show an excellent match between the simulated and measured data of both sea and land clutters. The close agreement between the model and the measurement clearly illustrates the validity and applicability of the model.

This work pertains to the use of superimposed training (ST) in closed loop multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. A novel method consisting of a technique to refine the channel estimate at the transmitter in a ST based closed loop MIMO-OFDM system is proposed. The estimate is refined at the transmitter by making use of the previous data that was transmitted. This significantly reduces the data interference in the channel estimate and hence improves performance. Two factors in general affect all transmitter side techniques that make use of the fed back channel coefficients. One is the quantization error affecting the channel estimate. The other is the channel variations that may render the fed back channel coefficients outdated for further use. The effect of these factors on the proposed refined channel estimation scheme is discussed in detail. Simulation results are presented in terms of the mean squared estimation error (MSEE) demonstrating the usefulness of the proposed scheme.

In this literature, we present a new method for estimating the coarse frequency offset in multi-band orthogonal frequency division multiplexing (MB-OFDM) based ultra-wideband (UWB) communication systems. The proposed training based coarse frequency offset (CFO) estimator performs an averaging of initial estimate over the multiple bands of transmission during estimation process. The proposed multi-band averaging provides an improved estimation of approximately three times for band group 1 (BG1) compared to our earlier proposed scheme. To prove the efficiency of the proposed scheme, the Cramer Rao lower bound (CRLB) of the estimation error is calculated and compared with the simulation results. We illustrate the performance of MB-OFDM system in terms of bit-error rate (BER) with multi-band averaged frequency synchronization (MBAFS) and compare with earlier reported results for 100,000 noisy realizations in UWB channel model 2 (CM2).

Energy consumption is an issue in general in information and communication technologies (ICT), but also cellular communications in particular. Base station sites are the main energy consumers in a mobile network. Their energy consumption significantly contributes to green house gas (CO2) emissions. Hence, service providers are looking for energy saving solutions in their existing and future deployments which in turn reduces the CO2 foot print and operational costs. There is a little study in assessing energy requirements of baseband functions of base station (e-nodeb) due to its energy consumption contribution is significantly low when compared to other more energy hungry components such as power amplifiers, analog frontend and protocols. In this paper, we have assessed energy consumption in MIMO-OFDM baseband functions of LTE eNodeB on a typical multi-core processor. In particular, implementing such computationally complex algorithms energy efficiently pose certain challenges such as less complex algorithm selection, architecture selection, algorithm architecture mapping, and energy management strategies. We have given the guide lines for addressing these challenges.

Energy consumption is an issue in general in information and communication technologies (ICT), but also cellular communications in particular. Therefore there is a need for assessing the hardware implementation methods used for cellular from energy consumption perspective. OFDM is a bandwidth efficient multiple access method. It is being used by all forms of future wireless mobilela communication systems including Long Term Evolution (LTE). The RF frontend, baseband algorithms and the protocols of these systems including 4G cellular need implementations with low power consumption, adequate processing speed, and low cost. In view of its importance and computational complexity, in this paper, three forms of implementing the baseband communication systems, including DSP, ASIC and RISC DSP based solutions are considered for the study of OFDM based multiple access methods of LTE through FFT algorithm.