Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726085
Chung Shue Chen, G. Øien
In this paper, we analyze the sum rate maximization problem in a two-cell wireless system under peak power and minimum service rate constraints. The optimal power allocation is found to be binary, in the sense that each base station power will have one out of only two possible discrete levels, and the result can greatly reduce the optimization and power control complexity required. A closed-form solution of the optimal assignment is reported. The new result provides a generalization of the binary power control (BPC) proposed in. It is possible to apply the new result under the two-cell structure when clustering a larger network into groups of two cells. In a comparison with the full power transmission, it is shown that the proposed scheme outperforms in both the outage probability and sum rate performance generally.
{"title":"Optimal power allocation for two-cell sum rate maximization under minimum rate constraints","authors":"Chung Shue Chen, G. Øien","doi":"10.1109/ISWCS.2008.4726085","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726085","url":null,"abstract":"In this paper, we analyze the sum rate maximization problem in a two-cell wireless system under peak power and minimum service rate constraints. The optimal power allocation is found to be binary, in the sense that each base station power will have one out of only two possible discrete levels, and the result can greatly reduce the optimization and power control complexity required. A closed-form solution of the optimal assignment is reported. The new result provides a generalization of the binary power control (BPC) proposed in. It is possible to apply the new result under the two-cell structure when clustering a larger network into groups of two cells. In a comparison with the full power transmission, it is shown that the proposed scheme outperforms in both the outage probability and sum rate performance generally.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121685414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726105
R. Mahapatra, M. Krusheel
In order to detect the presence of the primary user signal, spectrum sensing is a fundamental requirement to achieve the goal of cognitive radio (CR). This ensures the efficient utilization of the spectrum. Cyclostationary detection is the preferred technique to detect the primary users receiving data within the communication range of a CR user at very low SNR. In this work, we investigate the performance of maximal ratio combining (MRC) based cyclostationary detector to detect a primary user. Using the proposed detection technique, we observed that the MIMO cognitive radio enjoys 6 dB SNR advantage over single antenna when using four receive antennas for all values of probability of detection.
{"title":"Cyclostationary detection for cognitive radio with multiple receivers","authors":"R. Mahapatra, M. Krusheel","doi":"10.1109/ISWCS.2008.4726105","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726105","url":null,"abstract":"In order to detect the presence of the primary user signal, spectrum sensing is a fundamental requirement to achieve the goal of cognitive radio (CR). This ensures the efficient utilization of the spectrum. Cyclostationary detection is the preferred technique to detect the primary users receiving data within the communication range of a CR user at very low SNR. In this work, we investigate the performance of maximal ratio combining (MRC) based cyclostationary detector to detect a primary user. Using the proposed detection technique, we observed that the MIMO cognitive radio enjoys 6 dB SNR advantage over single antenna when using four receive antennas for all values of probability of detection.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131386156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726038
A. Bria, Alvaro Gonzalez Font
This paper describes and evaluates a novel resource management technique for minimizing the file transmission cost in a hybrid cellular-broadcasting system. While DVB-H technology is utilized for wide area broadcasting, the 3G-HSDPA system takes the role of providing not only feedback about reception conditions, but also on-demand repair information to the users that have missed part of the DVB-H transmissions. The application layer - forward error correction with Raptor coding is used to generate parity data that is sent to the users through both cellular and broadcasting system. Our results show significant potential for cost reduction under certain settings and scenarios. Overall, we think that the outcomes of this study should encourage the interworking of cellular 3G and DVB-H broadcasting systems, in an effort to achieve cost efficient delivery of multimedia content to mobile users.
{"title":"Cost-based resource management for filecasting services in hybrid DVB-H and 3G systems","authors":"A. Bria, Alvaro Gonzalez Font","doi":"10.1109/ISWCS.2008.4726038","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726038","url":null,"abstract":"This paper describes and evaluates a novel resource management technique for minimizing the file transmission cost in a hybrid cellular-broadcasting system. While DVB-H technology is utilized for wide area broadcasting, the 3G-HSDPA system takes the role of providing not only feedback about reception conditions, but also on-demand repair information to the users that have missed part of the DVB-H transmissions. The application layer - forward error correction with Raptor coding is used to generate parity data that is sent to the users through both cellular and broadcasting system. Our results show significant potential for cost reduction under certain settings and scenarios. Overall, we think that the outcomes of this study should encourage the interworking of cellular 3G and DVB-H broadcasting systems, in an effort to achieve cost efficient delivery of multimedia content to mobile users.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130074477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726047
T. Sakurai, M. Sawahashi, T. Kawamura, K. Higuchi
This paper proposes a two-step noise suppression method in the frequency and time domains for frequency domain channel estimation in single-carrier (SC)-FDMA radio access using a variable transmission bandwidth. In the proposed method, a weighted coherent averaging filter suppresses the noise component of the estimated channel gain in the frequency domain and then, after conversion of the channel gain into a time domain signal, effective path selection with threshold detection suppresses the noise component further. Computer simulation results show that the channel estimation with weighted coherent averaging in the frequency domain in addition to path selection employing threshold detection in the time domain improves the block error rate (BLER) by approximately 0.5 dB compared to that with path selection in the time domain only when the transmission bandwidth is one resource block (RB), i.e., 180 kHz, to four RBs, where paths are not sufficiently resolved. We also confirm that frequency domain channel estimation using only the threshold based path selection improves the BLER performance the most in a wide transmission bandwidth such as 25 RBs where sufficient path resolution accuracy is obtained.
{"title":"Effect of noise suppression in channel estimation for single-carrier FDMA radio access with variable transmission bandwidth","authors":"T. Sakurai, M. Sawahashi, T. Kawamura, K. Higuchi","doi":"10.1109/ISWCS.2008.4726047","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726047","url":null,"abstract":"This paper proposes a two-step noise suppression method in the frequency and time domains for frequency domain channel estimation in single-carrier (SC)-FDMA radio access using a variable transmission bandwidth. In the proposed method, a weighted coherent averaging filter suppresses the noise component of the estimated channel gain in the frequency domain and then, after conversion of the channel gain into a time domain signal, effective path selection with threshold detection suppresses the noise component further. Computer simulation results show that the channel estimation with weighted coherent averaging in the frequency domain in addition to path selection employing threshold detection in the time domain improves the block error rate (BLER) by approximately 0.5 dB compared to that with path selection in the time domain only when the transmission bandwidth is one resource block (RB), i.e., 180 kHz, to four RBs, where paths are not sufficiently resolved. We also confirm that frequency domain channel estimation using only the threshold based path selection improves the BLER performance the most in a wide transmission bandwidth such as 25 RBs where sufficient path resolution accuracy is obtained.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130853538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726068
Younsun Kim, Hongxiang Li, Hui Liu
The system capacity of a cellular wireless system consisting of a large number of fixed location base stations (BSs) and random location mobile stations (MSs) is studied. Assuming that the BSs in a multi-cell system are connected to a centralized controller which has access to channel state information (CSI), it is possible to optimize transmissions such that capacity is maximized. This paper discusses the theoretic limits of such cooperative multi-cell systems where a large number of BSs and MSs are involved. The evaluation is based on an accurate modeling of multi-cell deployment and practical BS per-antenna transmit power constraint. Performance results are obtained using numerical optimization and compared to the lower and upper bounds derived for different scenarios.
{"title":"Capacity of a multi-cell cooperative system","authors":"Younsun Kim, Hongxiang Li, Hui Liu","doi":"10.1109/ISWCS.2008.4726068","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726068","url":null,"abstract":"The system capacity of a cellular wireless system consisting of a large number of fixed location base stations (BSs) and random location mobile stations (MSs) is studied. Assuming that the BSs in a multi-cell system are connected to a centralized controller which has access to channel state information (CSI), it is possible to optimize transmissions such that capacity is maximized. This paper discusses the theoretic limits of such cooperative multi-cell systems where a large number of BSs and MSs are involved. The evaluation is based on an accurate modeling of multi-cell deployment and practical BS per-antenna transmit power constraint. Performance results are obtained using numerical optimization and compared to the lower and upper bounds derived for different scenarios.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133313385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726110
P. Kyritsi, P. Eggers, A. Oprea
Time reversal (TR) is a transmission technique that relies on pre-processing the signal at the transmitter (TX) by filtering it through a filter, the impulse response of which is a time reversed and phase conjugated version of the channel impulse response (CIR) to the target receiver (RX). TR is known to have remarkable temporal and spatial focusing properties. Specifically temporal focusing indicates that the perceived channel delay spread is reduced, and therefore we expect a less complicated equalizer to be required at the RX side to guarantee successful signal detection. In this paper we investigate how TR preprocessing affects the performance of finite minimum mean square error (MMSE) equalizers. The results are based on wideband measurements taken in an urban environment. We show that the application of TR is beneficial in the case of low signal to noise ratio (SNR) and low equalizer complexity.
{"title":"Measurement based performance evaluation of finite MMSE equalizers with and without time-reversal processing at the transmitter","authors":"P. Kyritsi, P. Eggers, A. Oprea","doi":"10.1109/ISWCS.2008.4726110","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726110","url":null,"abstract":"Time reversal (TR) is a transmission technique that relies on pre-processing the signal at the transmitter (TX) by filtering it through a filter, the impulse response of which is a time reversed and phase conjugated version of the channel impulse response (CIR) to the target receiver (RX). TR is known to have remarkable temporal and spatial focusing properties. Specifically temporal focusing indicates that the perceived channel delay spread is reduced, and therefore we expect a less complicated equalizer to be required at the RX side to guarantee successful signal detection. In this paper we investigate how TR preprocessing affects the performance of finite minimum mean square error (MMSE) equalizers. The results are based on wideband measurements taken in an urban environment. We show that the application of TR is beneficial in the case of low signal to noise ratio (SNR) and low equalizer complexity.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133661781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726067
H. Paaso, A. Mämmelä
Power amplifiers in a communication system are inherently nonlinear. Digital predistorters can compensate these nonlinearity effects. In this paper, two memory polynomial predistorters including direct and indirect learning architectures are compared with each other. To the best of our knowledge, no similar comparisons have been published. Both of these architectures are special cases of the self-tuning control. We have modeled predistorters and analysed nonlinear effects of a power amplifier and their digital compensation by using Matlab¿. Simulation results show that the memory polynomial model has convergence problems at large amplitudes and also problems of accuracy of representation. We observed that the results of the compensation depend also on the amplitude, not only on the frequency. The results of the linearisation show that the direct learning architecture achieves a better performance in almost all cases.
{"title":"Comparison of direct learning and indirect learning predistortion architectures","authors":"H. Paaso, A. Mämmelä","doi":"10.1109/ISWCS.2008.4726067","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726067","url":null,"abstract":"Power amplifiers in a communication system are inherently nonlinear. Digital predistorters can compensate these nonlinearity effects. In this paper, two memory polynomial predistorters including direct and indirect learning architectures are compared with each other. To the best of our knowledge, no similar comparisons have been published. Both of these architectures are special cases of the self-tuning control. We have modeled predistorters and analysed nonlinear effects of a power amplifier and their digital compensation by using Matlab¿. Simulation results show that the memory polynomial model has convergence problems at large amplitudes and also problems of accuracy of representation. We observed that the results of the compensation depend also on the amplitude, not only on the frequency. The results of the linearisation show that the direct learning architecture achieves a better performance in almost all cases.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116485118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726066
A. Gokceoglu, A. H. ghadam, M. Valkama
Feedforward linearization is one of the most well-known and widely-applied methods for linearizing power amplifiers (PA). In order to prevent performance degradation due to implementation inaccuracies, adaptive or self-designing structures utilizing e.g. gradient-descent type methods have been developed. Although the basic feedforward structure as such is insensitive to PA memory, the effects of memory on the adaptation behavior can be significant. In this paper, we present an analysis on the convergence of feedforward linearizer coefficients and the resulting reduction of inter-modulation distortion (IMD) when gradient-descent type adaptations are used with a PA that exhibits memory. A Hammerstein model is used for PA modeling, and computer simulations are used to demonstrate the validity and accuracy of the analysis.
{"title":"Effects of power amplifier memory on adaptive feedforward linearizers","authors":"A. Gokceoglu, A. H. ghadam, M. Valkama","doi":"10.1109/ISWCS.2008.4726066","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726066","url":null,"abstract":"Feedforward linearization is one of the most well-known and widely-applied methods for linearizing power amplifiers (PA). In order to prevent performance degradation due to implementation inaccuracies, adaptive or self-designing structures utilizing e.g. gradient-descent type methods have been developed. Although the basic feedforward structure as such is insensitive to PA memory, the effects of memory on the adaptation behavior can be significant. In this paper, we present an analysis on the convergence of feedforward linearizer coefficients and the resulting reduction of inter-modulation distortion (IMD) when gradient-descent type adaptations are used with a PA that exhibits memory. A Hammerstein model is used for PA modeling, and computer simulations are used to demonstrate the validity and accuracy of the analysis.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123207815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726084
P. Carvalho, J. Martins, Luís Bernardo, R. Dinis
Power control is a very important issue for any mobile node on a network, because of its limited battery power. If nodes use Code Division Multiple Access (CDMA) to share the available bandwidth, the transmitted power needs to be well controlled, to avoid the rise of noise level on the network and interferences with other nodes. The problem is even more difficult in ad-hoc networks, because there is no base station to control each node's transmitted power. This work presents a cross layer approach between the physical and logical layers to solve the power control problem, in ad-hoc networks, using low power CDMA nodes for indoor propagation channels. Our work uses a code acquisition and tracking system on the physical layer to determine the Transmitter - Receiver (TR) distance. This information is provided to the upper layer. It is also proposed a design of a simple, collision free and power efficient MAC protocol named "distance aware power control" (DAPC), which defines an exclusion region around the receptor to overcome CDMA classical Multiple Access Interference (MAI) problems, like the "near-far" problem.
由于电池电量有限，对于网络上的任何移动节点来说，电源控制都是一个非常重要的问题。当节点采用码分多址(CDMA)共享可用带宽时，需要很好地控制传输功率，以避免网络噪声水平的上升和对其他节点的干扰。这个问题在ad-hoc网络中更加困难，因为没有基站来控制每个节点的传输功率。这项工作提出了物理层和逻辑层之间的跨层方法，以解决在自组织网络中使用低功耗CDMA节点进行室内传播信道的功率控制问题。我们的工作使用物理层上的代码采集和跟踪系统来确定收发器(TR)距离。该信息提供给上层。本文还提出了一种简单、无碰撞、节能的MAC协议“距离感知功率控制”(distance - aware power control, DAPC)，该协议在接收器周围定义了一个排除区域，以克服CDMA经典的多址干扰(multi - Access Interference, MAI)问题，如“远近”问题。
{"title":"Effective power control in UWB systems using spreading code’s spatial resolution properties","authors":"P. Carvalho, J. Martins, Luís Bernardo, R. Dinis","doi":"10.1109/ISWCS.2008.4726084","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726084","url":null,"abstract":"Power control is a very important issue for any mobile node on a network, because of its limited battery power. If nodes use Code Division Multiple Access (CDMA) to share the available bandwidth, the transmitted power needs to be well controlled, to avoid the rise of noise level on the network and interferences with other nodes. The problem is even more difficult in ad-hoc networks, because there is no base station to control each node's transmitted power. This work presents a cross layer approach between the physical and logical layers to solve the power control problem, in ad-hoc networks, using low power CDMA nodes for indoor propagation channels. Our work uses a code acquisition and tracking system on the physical layer to determine the Transmitter - Receiver (TR) distance. This information is provided to the upper layer. It is also proposed a design of a simple, collision free and power efficient MAC protocol named \"distance aware power control\" (DAPC), which defines an exclusion region around the receptor to overcome CDMA classical Multiple Access Interference (MAI) problems, like the \"near-far\" problem.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122086724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-30DOI: 10.1109/ISWCS.2008.4726055
M. Al-Quzwini, S. N. Abdullah
In this paper an Improved RLS Based Adaptive MMSE Decision Directed MC-CDMA Receiver With Frequency Domain Interpolation (ImRLS-P) for Rayleigh Fading Channels is developed. The technique adopted by the ImRLS-P, is to reduce the noise components in the RLS-estimated channel frequency response before applying it to the MMSE adaptive detector and to reduce the computational rate as well. This is done by an IFFT, limiting window and an FFT. Simulation results in Rayleigh fading multiuser environments shows the ImRLS-P to outperforms the RLS in terms of BER and channel estimation average mean square error (AVMSE) with only an additional IFFT/FFT complexity increase. Furthermore, the ImRLS-P shows a comparable performance to that of the Pilot-Symbol-Aided approach for a mobile speed ¿ 60 km/h.
{"title":"Improved RLS Based Adaptive Decision Directed MC-CDMA Receiver With Frequency Domain Interpolation for Rayleigh Fading Channels","authors":"M. Al-Quzwini, S. N. Abdullah","doi":"10.1109/ISWCS.2008.4726055","DOIUrl":"https://doi.org/10.1109/ISWCS.2008.4726055","url":null,"abstract":"In this paper an Improved RLS Based Adaptive MMSE Decision Directed MC-CDMA Receiver With Frequency Domain Interpolation (ImRLS-P) for Rayleigh Fading Channels is developed. The technique adopted by the ImRLS-P, is to reduce the noise components in the RLS-estimated channel frequency response before applying it to the MMSE adaptive detector and to reduce the computational rate as well. This is done by an IFFT, limiting window and an FFT. Simulation results in Rayleigh fading multiuser environments shows the ImRLS-P to outperforms the RLS in terms of BER and channel estimation average mean square error (AVMSE) with only an additional IFFT/FFT complexity increase. Furthermore, the ImRLS-P shows a comparable performance to that of the Pilot-Symbol-Aided approach for a mobile speed ¿ 60 km/h.","PeriodicalId":158650,"journal":{"name":"2008 IEEE International Symposium on Wireless Communication Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128427856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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