Improvement of active interference cancellation: avoidance technique for OFDM cognitive radio

Huang, Shih-Gu; Hwang, Chien-Hwa

doi:10.1109/twc.2009.12.081277

Cited by 30 publications

(23 citation statements)

References 16 publications

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“…Nevertheless, the CC algorithm has been extensively investigated, and a number of modifications and combinations of the CC algorithm with other methods has been presented in the literature, e.g., refer to proposed approaches in [35][36][37]. For example, active interference cancellation (AIC) [33] is a method similar to CCs solution, where in addition to the OFDM edge-subcarriers several other subcarriers inside the PU transmission band are also used to minimize the OOB radiation.…”

Section: Cancellation Carriersmentioning

confidence: 99%

Protection of primary users in dynamically varying radio environment: practical solutions and challenges

Kryszkiewicz

Bogucka

Wyglinski

2012

J Wireless Com Network

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One of the primary objectives of deploying cognitive radio (CR) within a dynamic spectrum access (DSA) network is to ensure that the legacy rights of incumbent licensed (primary) transmissions are protected with respect to interference mitigation when unlicensed (secondary) communications are simultaneously operating within the same spectral vicinity. In this article, we present non-contiguous orthogonal frequency division multiplexing (NC-OFDM) as a promising and practical approach for achieving spectrally agile wireless data transmission that is suitable for secondary users (SUs) to access fragmented spectral opportunities more efficiently. Furthermore, a review of the current state-of-the-art is conducted with respect to methods specifically designed to protect the transmissions of the primary users (PUs) from possible interference caused by nearby SU transceivers employing NC-OFDM. These methods focus on the suppression of out-of-band (OOB) emissions resulting from the use of NC-OFDM transmission. To achieve the required OOB suppression, we present two practical approaches that can be employed in NC-OFDM, namely, the insertion of cancellation carriers and windowing. In addition to the theoretical development and proposed improvements of these approaches the computer simulation results of their performance are presented. Several real-world scenarios regarding the coexistence of both PU and SU signals are also studied using actual wireless experiments based on software-defined radio. These simulation and experimental results indicate that OOB suppression can be achieved under real-world conditions, making NC-OFDM transmission a viable option for CR usage in DSA networks.

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Section: Cancellation Carriersmentioning

confidence: 99%

Protection of primary users in dynamically varying radio environment: practical solutions and challenges

Kryszkiewicz

Bogucka

Wyglinski

2012

J Wireless Com Network

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“…In [14], a practical method for using multi-antenna radios to cancel interference in cognitive radio systems was proposed by using beamforming techniques to find antenna weights which place in the zero space at the primary receivers, which was efficient in reusing the band of a cellular network. In [15], the authors focused on complexity reduction and performance enhancement of the active interference cancellation for orthogonal frequency division multiplexing (OFDM) based CogNet, which reduced the number of subcarriers required to suppress the interference below a certain level. In [16], a distributed relay-assisted automatic repeat request (ARQ) method with active interference cancellation is proposed to serve heterogeneous elastic traffics with diverse quality of service (QoS) demands in cognitive radio systems, and the system throughput is analyzed.…”

Section: Introductionmentioning

confidence: 99%

Performance analysis of cognitive radio networks with interference cancellation

Song

Huang

et al. 2014

2014 IEEE Global Conference on Signal and Information Processing (GlobalSIP)

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This paper investigates the performance of cognitive radio network (CogNet). An interference cancellation scheme employed at secondary transmitter is first discussed based on the cancellation of cross interference from secondary transmitter to primary receiver. Then, we derive the expressions of the probability density function (PDF) and cumulative distribution function (CDF) of the received SNRs of both primary receiver and secondary receiver, and provide the closed-form overall outage probability expression of the system, which shows that the overall performance of the CogNet is improved with interference cancellation performed at the secondary transmitter. The numerical results finally verify the accuracy of our analysis.Index Terms-Cognitive radio networks, interference cancellation, overall outage probability.

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“…In classical CR systems, the users licensed to operate in a given band, usually entitled primary users (PUs), can share the radio spectrum usage with non-licensed users, hereafter denominated secondary users (SUs). Ultra Wideband (UWB) systems may allow an effective coexistence of PUs and SUs [1], [2] and, by decreasing the transmitting power of the SUs, the interference caused to the PUs may be actively controled [3]. UWB systems are also known by its large capacity when suffering interference from narrowband systems.…”

Section: Introductionmentioning

confidence: 99%

Detection of licensed users' activity in a random access ultra wideband cognitive system

Furtado

Luís

Irio

et al. 2014

2014 IEEE International Conference on Ultra-WideBand (ICUWB)

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In this work it is considered a ultra wideband cognitive radio network where multiple secondary users (SUs) communicate with an access point (AP) in an opportunistic way. The SUs adopt a distributed medium access control (MAC) scheme based on time contention through random medium access. One or multiple primary users (PUs) may become active in the entire band or in part of it, which may impact in the communications of the SUs. Departing from a classical random access scheme for the SUs, it is derived a solution to estimate the level of activity of the PUs through the observation of different data available at the MAC layer of each SU. Differently from the majority of the works already proposed, no physical spectrum sensing is needed to estimate the activity of the PUs since the estimation only relies on data collected at the MAC layer. Based on the level of PUs' activity detected by each SU, it is proposed a solution to regulate the SU's medium access in order to guarantee a given level of protection to the PUs. The formal methodology is evaluated through simulation and several results confirm the effectiveness of our proposal. 1

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Improvement of active interference cancellation: avoidance technique for OFDM cognitive radio

Cited by 30 publications

References 16 publications

Protection of primary users in dynamically varying radio environment: practical solutions and challenges

Protection of primary users in dynamically varying radio environment: practical solutions and challenges

Performance analysis of cognitive radio networks with interference cancellation

Detection of licensed users' activity in a random access ultra wideband cognitive system

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