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In this paper, we investigate the utilization of Raptor code for performance enhancement of Orthogonal Frequency Division Multiplexing (OFDM) systems. Unlike classical channel coding techniques which have fixed code rates, Raptor code is a rateless code. Raptor code has proved to have a wonderful performance over a class of wireless channels. Simul...
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Being spectrally efficient, easily implemented, and highly immune to selective channel imperfections and multipath fading, the Orthogonal Frequency Division Multiplexing (OFDM) can provide a sufficiently robust and high data rate modulation technique for emerging wired and wireless telecommunication applications. However, a major drawback of OFDM t...
Citations
... MacKay [17], discusses the key benefits of Fountain codes over AWGN and fading channels in terms of effectiveness, toughness, and dependability [18,19]. ...
... In a Rayleigh fading channel, Khoueiry and Soleymani proposed a system that assessed the effectiveness of combining the LDPC technique with Raptor codes [35]. The BER of the codeless OFDM system was improved by implementing a Raptor-coded OFDM system with Binary Phase Shift Keying (BPSK), which was shown to offer improved error performance for OFDM over AWGN channels [18] Kadoch and Benzida proposed a comprehensive design for a massive MIMO communication system. The receiver uses Raptor decoding symbols in conjunction with the MMSE technique, which estimates the channel without using pilot symbols at the receiver [36]. ...
... Raptor codes are a class of fountain codes [18]. It is the combination of an LT code and the precode, a high-rate error correction code, which is the outer code. ...
Low signal to noise ratio (SNR) channels require careful design of communication systems in order to operate reliably in such extreme channels. Special measures and techniques must be considered when designing communication systems for such environments to counteract the effect of high noise power. Channel coding is a powerful tool to aid against adverse channel conditions including low SNR. Coupling channel coding with a spreading technique can further strengthen the performance of communication systems. Hence, we studied the performance of a system that combines Raptor codes with direct sequence code division multiple access (DS-CDMA) in low SNR scenarios. The studied design can operate in a wide range of low SNR values. Simulation results show that the system can offer satisfactory BER performance at different code rates. Also, combining Raptor codes with DS-CDMA showed an improvement of approximately 6 dB when compared with other schemes using DS-CDMA in low SNR conditions.
... The error coding schemes are the first class, and they are used to protect data transmitted from noise, attenuation or distortion. The second class is erasure coding, which is designed to safeguard data against loss caused by packet collisions or wireless congestion [38]. ...
... The original data is encoded using an appropriate error correction method. In the case that some data is lost during transmission, the lost data can be recovered utilizing erasure techniques [38]. Turbo code [31] is an error correction code with a near-channel capacity performance that reduces data bit error rate to about zero. ...
... The encoder for LT codes is capable of producing an endless number of encoding symbols. The LT code decoder can recover all of the input symbols whenever the number of encoded symbols received is somewhat larger than the number of the input symbols [38]. ...
... Classical FEC schemes are an efficient Quality of Service (QoS) tool in wireless communication systems. Although these error control techniques have fixed code rates, it contains two main categories, the block codes and the convolutional codes [12]. ...
Due to the importance of both rate‐less digital fountain codes and Multi‐Input Multi‐Output (MIMO) schemes in Fifth and Sixth Generation (5G/6G) wireless networks, this paper investigates enhancing the performance of MIMO‐Orthogonal Frequency Division Multiplexing (MIMO‐OFDM) based system by employing the rate‐less fountain codes. The rate‐less codes, such as the Tornado codes and Raptor codes, have a flexible code rate that differs from the classical channel coding schemes. This paper uses Raptor code to study the MIMO system's performance with the rate‐less codes over different wireless communications channels. The proposed MIMO‐fountain code‐based system has been tested over the various wireless communication channel conditions concerning the varied Frequency Doppler (FD). In the proposed rate‐less wireless communication system, multiple interleaving techniques and equalizers are used to improve its performance. Computer‐based simulation experiments are assigned to evaluate the MIMO‐fountain code system using the different data transmission scenarios. Simulation results confirm the superiority of the presented wireless rate‐less system compared to fixed‐rate wireless systems in terms of Bit Error Rate (BER) and throughput.
... In the paper, MacKay [13] fountain code, also referred to as rateless code, is a new member of the channel coding family that can produce an infinite number of encoding symbols from a set of source symbols k. In the paper, MacKay [13] demonstrates the essential advantages of fountain codes related to efficiency, durability, and reliability over the AWGN channel and fading channels [14], [15]. The luby-transform (LT) codes are a practical class of fountain codes. ...
... In the paper, Khoueiry and Soleymani [28] proposed a system that evaluated combining the LDPC technique and raptor codes in a rayleigh fading channel. In the paper, El-Gohary et al. [14], a raptor-coded OFDM system with binary phaseshift keying (BPSK) was implemented for improving the BER of the codeless OFDM system, which was verified to offer enhanced error performance for OFDM over AWGN channels. In the paper, Benzida and Kadochb [29] suggested a new scheme for a massive MIMO communication system. ...
... Raptor code is considered a more advanced variant of the LT code with low computational cost and the potential to minimize channel effects [14]. It incorporates the benefits of block and Fountain codes to construct modern Fountain codes with linear encoded and decoded techniques. ...
Some kinds of communication systems work in very low signal-to-noise (LSNR) environments. For these systems to function reliably, specific techniques and methodologies have to be used to mitigate the degrading effects of the channel. The channel coding method is the key element in most LSNR communication systems, but emphasizing the code division multiple access (CDMA) is a new transmission technique in these channels. To enhance the CDMA scheme's system capacity and reach unprecedented ranges of LSNR values in wireless sensor network. This paper suggests combining CDMA with certain types of channel coding algorithms, such as the raptor codes. The raptor channel encoding technique has improved the CDMA system's performance when using binary phase-shift keying (BPSK) modulation in additive white gaussian noise (AWGN) channels. It has achieved a low bit error rate in range of 10-7 at Eb/No value of (-3) dB and about 10-6 at shannon's limit. The Raptor-coded CDMA scheme works well for channel signal to noise ration (SNR) values of greater than -9 dB, showing an improvement of about 7 dB compared with turbo/convolutional channel coding methods used with the CDMA system bit error rate (BER) and throughput. On the other hand, it has been shown that the convolutional encoder presents the weakest performance compared to both the turbo and raptor codes.</span
... It is designed specifically for reliable communication across an erasure channel with an unknown erasure probability. MacKay in [13] demonstrates the essential advantages of Fountain codes related to efficiency, durability, and reliability over the AWGN channel as well as over fading channels [14] [15]. A practical class of Fountain codes is known as Luby-Transform (LT) codes [16]. ...
... Khoueiry and Soleymani proposed a system that evaluated a combination of the LDPC technique and Raptor codes in a Rayleigh fading channel [26]. In [14], a Raptor-coded OFDM system with Binary Phase Shift Keying (BPSK) was implemented for improving the BER of the codeless OFDM system, which was verified to offer enhanced error performance for OFDM over AWGN channels. M. Kadochb and D. Benzida suggested a new scheme for a massive MIMO communication system. ...
... Raptor code is considered as a more advanced variant of the LT code with low computational cost and the potential for minimizing channel effects [14]. It incorporates the advantages of block and Fountain codes to construct modern Fountain codes with linear encoding and decoding techniques. ...
Some kinds of communication systems work in very low signal to noise power ratio (SNR) environments. For these systems to function reliably, certain techniques and methodologies have to be used to mitigate the degrading effects of the channel.The channel coding method is the key element in most low SNR communication systems with emphasis on the Code Division Multiple Access (CDMA) as a recommended transmission technique in these channels. To enhance the system capacity of the CDMA scheme and reach to unprecedented ranges of low SNR values in systems like the Wireless Sensor Network (WSN), this paper suggests a technique for combining CDMA with certain types of channel coding algorithms such as the Raptor codes. The Raptor channel encoding technique has shown an improved performance for the CDMA system when using BPSK digital modulation in AWGNchannels. It has achieved a low bit error rate in the range of 10 ⁻⁶ at E b /N o value of -2 dB and 10 ⁻⁷ at E b /N o value of -3 dB for code rates 1/2 and 1/3 resprctively. The Raptor-coded CDMA scheme showing an improvement of about 6 dB when compared with some other channel coding methods used with the CDMA system for the same BER.
... RQ codes operate very close to ideal codes which has zero reception ( = 0 ) overhead and has improved coding efficiency for different range of source block sizes compared with R10, which requires K ≥ 1000 [3]. In practice using small block sizes is better for devices with limited power and processing capability such as mobile phones [17]. In this work at some points Raptor codes and RQ codes used interchangeable. ...
This paper presents a reliable and efficient high quality video streaming solution for use in challenging outdoor environments over Wi-Fi. An application layer forward error correction based on RaptorQ codes was implemented in a practical Wi-Fi based server and client system to enhance reliability. Thus, this paper presents the first detailed analysis on the implementation of RaptorQ codes for streaming high definition video over Wi-Fi. The measurements were performed in central Bristol with parameters such as RaptorQ symbol size, code rate, buffering time and modulation and coding scheme, and user quality of experience based on these parameters was evaluated. For multicast live video streaming it is demonstrated that system performance is mostly dominated by hardware and software limitations on constrained host platforms where the incoming packet rate exceeds the device`s ability to consume the traffic, i.e., Wi-Fi clients are a major source of packet loss, even in ideal channel conditions. Client limitations were found to be a function of modulation and coding schemes and RaptorQ coding parameters. Therefore, the optimum system design parameters such as RaptorQ symbol size, code rate and buffering time with respect to modulation and coding schemes were suggested considering practical limitations from real-world measurements.
... RQ codes operate very close to ideal codes which has zero reception ( = 0) overhead and has improved coding efficiency for different range of source block sizes compared with R10, which requires K ≥ 1000 [3]. In practice using small block sizes is better for devices with limited power and processing capability such as mobile phones [17]. In this work at some points Raptor codes and RQ codes used interchangeable. ...
... When different RQ symbol sizes were compared, it was found that larger packet size provided better results than small packet, i.e., higher decoding success rates were observed for locations with good channel conditions. However, the use of small symbol size provided better user QoE for locations 17 with bad channel conditions, especially when higher MCS modes used. As a conclusion, this paper provided a unique insight into the real-time implementation of RQ codes in a practical Wi-Fi multicast video streaming system. ...
This paper presents a reliable and efficient high quality video streaming solution for use in challenging outdoor environments over Wi-Fi. An application layer forward error correction based on RaptorQ codes was implemented in a practical Wi-Fi based server and client system to enhance reliability. Thus, this paper presents the first detailed analysis on the implementation of RaptorQ codes for streaming high definition video over Wi-Fi. The measurements were performed in central Bristol with parameters such as RaptorQ symbol size, code rate, buffering time and modulation and coding scheme, and user quality of experience based on these parameters was evaluated. For multicast live video streaming it is demonstrated that system performance is mostly dominated by hardware and software limitations on constrained host platforms where the incoming packet rate exceeds the device`s ability to consume the traffic, i.e., Wi-Fi clients are a major source of packet loss, even in ideal channel conditions. Client limitations were found to be a function of modulation and coding schemes and RaptorQ coding parameters. Therefore, the optimum system design parameters such as RaptorQ symbol size, code rate and buffering time with respect to modulation and coding schemes were suggested considering practical limitations from real-world measurements.
... The encoding of Raptor code can be divided into two steps. As long as a sufficient number of intermediate symbols can be recovered by the LT code decoding phase, the source symbols can be obtained by decoding intermediate symbols (El-Gohary et al. 2017). This is due to the addition of the precoding process. ...
Aiming at the wireless channel in which the state of video surveillance communication network changes dramatically, to ensure the video impact under a restricted channel bandwidth condition, an application layer forward error correction system for wireless video communication is proposed. This scheme is an improved forward error correction algorithm. The most appropriate redundancy amount is implemented for each FEC block by constantly altering the redundancy in FEC blocks. Firstly, the system describes and implements the optimum video transmission. Then, the RCPC code and Raptor code are used as forward error correction codes in physical layer and application layer respectively, in this way, the optimal system solution can be acquired. In the forward error correction technology, a feedback mechanism is then developed between the receiver and the sender, which will acknowledge that the receiver can extract the packet loss rate from the received speech signal in the current network state in real time, and then the packet loss rate will be transferred back to the sender by the feedback mechanism. The sender can modify the forward packet loss rate according to the packet loss rate. The error-correcting schema can help the next speech signal have the most appropriate forward error-correcting redundancy, reducing bandwidth waste, significantly improving the adaptability and efficiency of forward error-correcting technology in the wireless network. The simulation results show that the average video quality of the proposed scheme is 0.5–4 dB higher than that of the equal error protection scheme and the extended window unequal error protection scheme.
... A different channel access method was introduced in 4G's LTE known as Orthogonal Frequency Division Multiple Access (OFDMA) for downlink. OFDMA was brought in to make use of the spectrum more efficiently as seen in Figure 4 [23]. This efficiency was achieved by OFDMA as it eliminates the need of guard bands. ...
This paper discusses how the mobile telephony generations have come up over the years along with what is in-store in the future generations. The paper highlights each generation's features and drawbacks. It brings forth the different technologies and standards used in each generation. Finally, considering all the generations, observations are made.
The pseudo-coding can be considered of the coding techniques which are utilized for combating the effects of noise on the transmitted signals. This chapter presents the pseudo-coding using different interleaving techniques. The traditional and proposed randomizing techniques are presented in this chapter. The historical note of the chaotic encryption is discussed. It is employed in this chapter as the proposed pseudo-code. The image transmission over the WPAN Bluetooth networks is discussed in this chapter.
