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In this paper, a novel simplified statistical approach to evaluate the error performance bound of Ordered Statistics Decoding (OSD) of Linear Block Codes (LBC) is investigated. First, we propose a novel statistic which depicts the number of errors contained in the ordered received noisy codeword. Then, simplified expressions for the probability mass function and cumulative distribution function are derived exploiting the implicit statistical independence property of the samples of the received noisy codeword before reordering. Second, we incorporate the properties of this new statistic to derive the simplified error performance bound of the OSD algorithm for all order−I reprocessing. Finally, with the proposed approach, we obtain computationally simpler error performance bounds of the OSD than those proposed in literature for all length LBCs.

In this paper, the effect of primary user (PU) traffic on the performance of largest eigenvalue based spectrum sensing technique (Roy's Largest Root Test (RLRT)) is investigated. A simple and realistic discrete time modeling of PU traffic is considered which is only based on the discrete time distribution of PU free and busy periods. Furthermore, in order to analyze the effect of PU traffic on the detection performance, analytical expressions for the probability density functions of the decision statistic are derived and validated by Monte-Carlo simulations. Numerical results demonstrate that the sensing performance of RLRT is no more monotonically increasing with the length of the sensing duration and also with SNR which contrasts with the common property of the spectrum sensing techniques under known PU traffic scenario. Furthermore, it is shown that the performance gain due to the multiple antennas in the sensing unit is significantly suppressed by the effect of the PU traffic when the frequency of the PU traffic transitions is higher.

In this paper, semi-blind class of spectrum sensing algorithms, Energy Detection (ED) and Roy's Largest Root Test (RLRT), are considered under a typical flat fading channel scenario. The knowledge of the noise variance is imperative for the optimum performance of ED and RLRT. Unfortunately, the variation and unpredictability of noise variance is unavoidable. An idea of auxiliary noise variance estimation is introduced in order to cope with the absence of prior knowledge of the noise variance, thus a hybrid approach of signal detection is set forth for each considered method. The detection performance of the methods are derived and expressed by closed form analytical expressions. The impact of noise estimation accuracy on the the performance of ED and RLRT is compared in terms of Receiver Operating Characteristic (ROC) curves and performance curves (Probability of Detection/Miss-detection as a function of SNR by fixing the false alarm probability). It is concluded that optimum performance of ED and RLRT can be achieved even with the use of estimated noise variance by using a large number of slots for variance estimation. Finally, it is also found out that the impairment due to noise uncertainty is reduced on RLRT w. r. t. ED.

Oyster mushroom (Pleurotus oestratus) has outstanding flavor and taste with fan shaped pileus which is rich source of both macro and micro nutrients. It is of paramount importance to choose appropriate substrates in a given place to grow oyster mushroom successfully. The experiment was conducted at Bangaun, Lamahi, Dang, Nepal during 2018-19 to study the growth performance of oyster mushroom on locally available substrates as well as to find out the best substrate. The substrates used in the experiment were lentil straw, rice straw, wheat straw, maize stover, maize cob, along with the mix ratio of corn cob 1:3 with these substrates under factorial completely randomized design (CRD) design with four replications during winter season with an average daily temperature of 12-21°C and RH ranging from 80 to 90%. Among the tested substrate composition, significantly the lowest days (17.5 days) to complete spawn running was recorded on maize cob followed by lentil straw (22.5 days) while highest days (30.75 days) was required to complete spawn running on rice straw. The lowest time (25.50 days) for first fruiting initiation, the lowest time (33 days) for harvesting and the highest yield (2.47 kg) was revealed by lentil straw. The highest pileus diameter (6.81 cm) was recorded on wheat straw followed by rice and maize cob mix at 3:1 ratio (6.58 cm). Lentil straw was found the best substrate and rice straw mix with maize cob was more efficient as compared to rice straw only for the production of Pleurotus ostreatus mushroom.