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The purpose of this paper is to introduce the analysis and performance of a hybrid multiple access scheme which combines interleave division multiple access (IDMA) and code division multiple access (CDMA), referred to as IDMA/CDMA. With experimentations, the scheme can achieve good performance with simple user ends for the system.

IDMA technique is employed as the uplink transmission and CDMA technique as the downlink transmission. The performance comparison of IDMA and IDMA/CDMA downlink is studied with Monte Carlo simulations to investigate the bit error rates. For IDMA/CDMA downlink, the signals are interleaved by random interleavers, spreaded by M‐sequence and orthogonal Gold sequence, respectively, and then transmitted over an AWGN with BPSK modulation. Moreover, a channel estimation approach for IDMA based on expectation maximization (EM) algorithm is also presented.

The multi‐user detection (MUD) algorithm in uplink IDMA systems is much simpler than that used in traditional CDMA systems. It is also well known that the orthogonal spreading codes in CDMA can effectively help suppress the MAI in the synchronized environments. But for the asynchronized application, the performance of CDMA systems will degrade due to the serious multiple user interference. According to traditional IDMA and orthogonal code division multiple access/IDMA signal detection algorithms, every UE has to detect all of the signals of other users for iterative detection. The advantages of IDMA and CDMA technologies can be utilized substantially.

The proposed hybrid multiple access scheme can achieve a very simple chip‐by‐chip iterative MUD strategy at base station, and the simplified receiving operation at UE. On the other hand, this paper also evaluates channel estimation approach for IDMA based on EM algorithm.

This paper focuses on searching for the conditions of cooperation in collaborative technology innovation including the Government and private enterprises. After assuming the collaborative project of code division multiple access (CDMA) as one of the collective actions, attempts to analyze the case of CDMA technology development process by applying the theoretical propositions derived from two approaches, collective action andprisoner dilemma. Identifies government’s roles and strategies as a third party who guarantees the realistic conditions for cooperation to induce the success of joint ventures which inherently have the potential risk of cooperation collapse caused by the opportunistic or free‐riding behaviors of private collaborators as self‐interest seekers. Finally, suggests therealistic conditions for cooperation, government’s roles, and policy tools for the future collaborative R&D.

In code‐division multiple‐access (CDMA) systems, the number of mobile users that each cell can support is limited by the total received power or interference received at each base station (BS) and can vary with time. The total received power can be used as an indicator of traffic load in call admission control. In this paper, we propose a call admission control (CAC) scheme based on the total received power for CDMA systems supporting integrated voice/data services. Based on the current measure of the received power, we develop an algorithm to estimate the updated total received power due to a new incoming call. We analyze the optimal admission threshold for both power limited cells and interference limited cells. We model the system by a multi‐dimensional Markov chain and compute the system performance in terms of new call blocking probability, forced termination probability of voice calls, average transmission delay of data calls and outage probability. We compare our results with an existing degradation scheme.

The purpose of this paper is to propose a new optical steganography framework that can be applied to public optical binary phase-shift keying (BPSK) systems by transmitting a stealth spectrum-amplitude-coded optical code-division multiple-access signal through a BPSK link.

By using high-dispersion elements, the stealth data pulses temporally stretch and the amplitude of the signal decreases after stretching. Thus, the signal can be hidden underneath the public signal and system noise. At the receiver end, a polarizer is used for removing the public BPSK signal and the stealth signal is successfully recovered by a balanced detector.

In a simulation, the bit-error rate (BER) performance improved when the stealth power increased.

The BER performance worsens when the noise power become large. Future work will consider increasing the system performance during high-noise power situation.

By properly adjusting the power of the amplified spontaneous emission noise, the stealth signal can be hidden well in the public channel while producing minimal influence on the public BPSK signal.

In conclusion, the proposed optical steganography framework makes it more difficult for eavesdroppers to detect and intercept the hidden stealth channel under public transmission, even when using a dispersion compensation scheme.

The purpose of this paper is to investigate the use of 802.11e MAC to resolve the transmission control protocol (TCP) unfairness.

The paper shows how a TCP sender may adapt its transmission rate using the number of hops and the standard deviation of recently measured round‐trip times to address the TCP unfairness.

Simulation results show that the proposed techniques provide even throughput by providing TCP fairness as the number of hops increases over a wireless mesh network (WMN).

Future work will examine the performance of TCP over routing protocols, which use different routing metrics. Other future work is scalability over WMNs. Since scalability is a problem with communication in multi‐hop, carrier sense multiple access (CSMA) will be compared with time division multiple access (TDMA) and a hybrid of TDMA and code division multiple access (CDMA) will be designed that works with TCP and other traffic. Finally, to further improve network performance and also increase network capacity of TCP for WMNs, the usage of multiple channels instead of only a single fixed channel will be exploited.

By allowing the tuning of the 802.11e MAC parameters that have previously been constant in 802.11 MAC, the paper proposes the usage of 802.11e MAC on a per class basis by collecting the TCP ACK into a single class and a novel congestion control method for TCP over a WMN. The key feature of the proposed TCP algorithm is the detection of congestion by measuring the fluctuation of RTT of the TCP ACK samples via the standard deviation, plus the combined the 802.11e AIFS and CW_min allowing the TCP ACK to be prioritised which allows the TCP ACKs will match the volume of the TCP data packets. While 802.11e MAC provides flexibility and flow/congestion control mechanism, the challenge is to take advantage of these features in 802.11e MAC.

With 802.11 MAC not having flexibility and flow/congestion control mechanisms implemented with TCP, these contribute to TCP unfairness with competing flows.

The suggested work examines the latest developments such as the techniques employed for allocation of power, browser techniques, modern analysis and bandwidth efficiency of nonorthogonal multiple accesses (NOMA) in the network of 5G. Furthermore, the proposed work also illustrates the performance of NOMA when it is combined with various techniques of wireless communication namely network coding, multiple-input multiple-output (MIMO), space-time coding, collective communications, as well as many more. In the case of the MIMO system, the proposed research work specifically deals with a less complex recursive linear minimum mean square error (LMMSE) multiuser detector along with NOMA (MIMO-NOMA); here the multiple-antenna base station (BS) and multiple single-antenna users interact with each other instantaneously. Although LMMSE is a linear detector with a low intricacy, it performs poorly in multiuser identification because of the incompatibility between LMMSE identification and multiuser decoding. Thus, to obtain a desirable iterative identification rate, the proposed research work presents matching constraints among the decoders and identifiers of MIMO-NOMA.

To improve the performance in 5G technologies as well as in cellular communication, the NOMA technique is employed and contemplated as one of the best methodologies for accessing radio. The above-stated technique offers several advantages such as enhanced spectrum performance in contrast to the high-capacity orthogonal multiple access (OMA) approach that is also known as orthogonal frequency division multiple access (OFDMA). Code and power domain are some of the categories of the NOMA technique. The suggested research work mainly concentrates on the technique of NOMA, which is based on the power domain. This approach correspondingly makes use of superposition coding (SC) as well as successive interference cancellation (SIC) at source and recipient. For the fifth-generation applications, the network-level, as well as user-experienced data rate prerequisites, are successfully illustrated by various researchers.

The suggested combined methodology such as MIMO-NOMA demonstrates a synchronized iterative LMMSE system that can accomplish the optimized efficiency of symmetric MIMO NOMA with several users. To transmit the information from sender to the receiver, hybrid methodologies are confined to 2 × 2 as well as 4 × 4 antenna arrays, and thereby parameters such as PAPR, BER, SNR are analyzed and efficiency for various modulation strategies such as BPSK and QAM_j (j should vary from 8,16,32,64) are computed.

The proposed hybrid MIMO-NOMA methodologies are synchronized in terms of iterative process for optimization of LMMSE that can accomplish the optimized efficiency of symmetric for several users under different noisy conditions. From the obtained simulated results, it is found, there are 18%, 23% 16%, and 8% improvement in terms of Bit Error Rate (BER), Least Minimum Mean Squared Error (LMMSE), Peak to Average Power Ratio (PAPR), and capacity of channel respectively for Binary Phase Shift Key (BPSK) and Quadrature Amplitude Modulation (QAM) modulation techniques.

This article examines the dynamics of wireless R&D as a combined function of technology and market evolution, focusing on the management and organization of wireless R&D. From the postwar era to the late 1990s, the management and organization of wireless R&D capabilities has been effectively reversed. Industry thrust has shifted from closed specifications, central innovation and domestic market to open specifications, distributed innovation and global networking. The old era is reflected by the classic Bell Labs; the new era by Nokia. Due to the alternation of sustaining and disruptive change, no wireless company can survive without incessant innovation. In this rivalry, the winners are companies that best match their organizational capabilities with the changing industry opportunities.

The purpose of this paper is to discuss the development of high‐tech industry and the dynamics of technological learning, innovation, entrepreneurship in China through the telecom‐equipment industry.

The paper derives a number of research propositions from the literature and then uses four case studies to show how domestic firms narrow their technological gap in different stages of catch‐up and how these firms have been influenced by their innovation capabilities to catch up to the multinationals.

The major findings of the paper may be summarized as follows. First, the innovation capability and self‐developed technologies have been the key to leading domestic firms in catching‐up with the MNCs. Second, leading domestic firms mainly depend on in‐house R&D development, supplemented with external alliance to build their innovation capability. Third, there are two different catching‐up patterns in China's telecom‐equipment industry. One is “path‐following” catching‐up in global system for mobile communication driven by using new technology in low‐end market. The other is “leapfrogging” catching‐up in the development of phone digital switches and China's own 3G standard (time division – synchronous code division multiple access). However, it seems that the leapfrogging strategy will meet more challenges and problems than the path‐following strategy.

Based on the previous researches about technological learning, innovation and catch‐up in the newly industrializing economies, the paper provides a comprehensive elaboration in Chinese telecommunication industry by using case study approach in an original way.

The main purpose of the current work is high quality video transmission over cognitive radio wireless networks.

A soft computing technique based on fuzzy logic concept is introduced that can reduce the blocking probability and increase the perceived quality of video users.

It is found that by using soft computing techniques it is possible to increase the perceived quality and reduce the blocking probability in cognitive radio networks for secondary video users.

The main originality of this paper is twofold: at first the design philosophy in admission is quality of experience centric and second, soft computing techniques are used to decrease the blocking probability in cognitive networks.