Dynorphin peptides and the kappa-opioid receptor are important in the rewarding properties of coc... more Dynorphin peptides and the kappa-opioid receptor are important in the rewarding properties of cocaine, heroin, and alcohol. We tested polymorphisms of the prodynorphin gene (PDYN) for association with cocaine dependence and cocaine/alcohol codependence. We genotyped six single nucleotide polymorphisms (SNPs), located in the promoter region, exon 4 coding, and 3' untranslated region, in 106 Caucasians and 204 African Americans who were cocaine dependent, cocaine/alcohol codependent, or controls. In Caucasians, we found point-wise significant associations of 3'UTR SNPs (rs910080, rs910079, and rs2235749) with cocaine dependence and cocaine/alcohol codependence. These SNPs are in high linkage disequilibrium, comprising a haplotype block. The haplotype CCT was significantly experiment-wise associated with cocaine dependence and with combined cocaine dependence and cocaine/alcohol codependence (false discovery rate, q=0.04 and 0.03, respectively). We investigated allele-specific gene expression of PDYN, using SNP rs910079 as a reporter, in postmortem human brains from eight heterozygous subjects, using SNaPshot assay. There was significantly lower expression for C allele (rs910079), with ratios ranging from 0.48 to 0.78, indicating lower expression of the CCT haplotype of PDYN in both the caudate and nucleus accumbens. Analysis of total PDYN expression in 43 postmortem brains also showed significantly lower levels of preprodynorphin mRNA in subjects having the risk CCT haplotype. This study provides evidence that a 3'UTR PDYN haplotype, implicated in vulnerability to develop cocaine addiction and/or cocaine/alcohol codependence, is related to lower mRNA expression of the PDYN gene in human dorsal and ventral striatum.
To examine if the genes encoding the pleckstrin homology domain–containing protein gene (PLEKHA1)... more To examine if the genes encoding the pleckstrin homology domain–containing protein gene (PLEKHA1), hypothetical LOC387715/ARMS2 gene, and HtrA serine peptidase 1 gene (HTRA1) located on the long arm of chromosome 10 (10q26 region) confer risk for neovascular age-related macular degeneration (AMD) in an independent or interactive manner when controlling for complement factor H gene (CFH) genotype and smoking exposure.Retrospective matched-pair case–control study.Hospital clinic-based sample of 134 unrelated patients with neovascular AMD who have a sibling with normal maculae (268 subjects).Disease status was ascertained by at least 2 investigators by review of fundus photographs and/or fluorescein angiography according to the Age-Related Eye Disease Study grading scale. If necessary, a home retinal examination was performed (n = 6). A combination of direct sequencing and analysis of 8 highly polymorphic microsatellite markers was used to genotype 33 megabases of the 10q26 region on leukocyte DNA. Smoking history was obtained via a standardized questionnaire and measured in pack-years. The family-based association test, haplotype analysis, multiple conditional logistic regression, and linkage analysis were used to determine significant associations.Neovascular AMD status.Of the 23 variants we identified in the 10q26 region, 6 were significant. Four of the 6 were novel and included 2 genotypes that reduced risk of AMD. Many single-nucleotide polymorphisms (SNPs), including the previously reported variants rs10490924 (hypothetical LOC387715/ARMS2) and rs11200638 (HTRA1), defined 2 significant haplotypes associated with increased risk of neovascular AMD. The coding HTRA1 SNP rs2293870, not part of the significant haplotypes containing rs10490924 and rs11200638, showed as strong an association with increased susceptibility to neovascular AMD. Linkage analysis supported our findings of SNP association (P<10−15). No significant interactions were found between any of the SNPs in the 10q26 and smoking or between these SNPs and CFH genotype.Independent of CFH genotype or smoking history, an individual's risk of AMD could be increased or decreased, depending on their genotype or haplotype in the 10q26 region.
Polyacrylonitrile fiber (PANF) was modified by alcoholysis reaction and the efficiencies of the P... more Polyacrylonitrile fiber (PANF) was modified by alcoholysis reaction and the efficiencies of the PANF and the modified polyacrylonitrile fiber (MPANF) for oil removal were investigated. Fourier transform infrared (FTIR) spectroscopy revealed that new organophilic functional groups were grafted on the fiber surface. Scanning electron microscopy (SEM) showed that the alcoholysis process made the surface of the MPANF rougher than that of the PANF. Oil sorption tests of the PANF and the MPANF for motor oil SAE 30, motor oil SAE 50, and multigrade engine oil (MEO) were carried out in batch tank (in water and in oil without water), and the MPANF showed higher oil sorption capacity compared to the PANF. Dynamic sorption of diesel oil-in-water emulsion (initial oil concentration of 630 mg/dm3) was investigated in coalescing bed. The experiments in the coalescing bed indicated that the MPANF could resist higher interstitial velocity, as compared to the PANF. More than 97% of oil content in the influent stream could be removed by the MPANF bed under the optimum condition. The results indicated that reuse of the PANF as oil sorbent was quite feasible.
A cis-9-octadecenoic acid (OA) surface-modified TiO2 nanoparticle with average diameter of 30nm w... more A cis-9-octadecenoic acid (OA) surface-modified TiO2 nanoparticle with average diameter of 30nm was chemically synthesized. The tribological properties of the prepared OA–TiO2 nanoparticle as an additive in water were evaluated with a four-ball tester. The results show that the OA–TiO2 nanoparticle exhibits good antiwear and friction reduction properties as well as load-carrying capacity. The maximum non-seizure load (PB value) can
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
ABSTRACT A new composite adsorbent, zeolite/cellulose acetate blend (ZCAB) fiber, was prepared by... more ABSTRACT A new composite adsorbent, zeolite/cellulose acetate blend (ZCAB) fiber, was prepared by wet spinning method. The scanning electron micrograph results showed that the zeolite particles were retained and wrapped in the networks of the ZCAB fiber. The adsorption of Cu(II) from aqueous solution by ZCAB fiber was studied in a packed bed. The effects of several parameters, such as the pH of solution, initial metal concentration, bed depth and flow rate, were investigated. The breakthrough data were well described by Thomas model, and the service time at different initial concentrations and flow rates was also predicted by the bed depth service time (BDST) model. The dynamic treatment of electroplating wastewater by the ZCAB fiber bed was also assessed, and the saturated column could be regenerated using HCl solution. About 2.1 L of electroplating wastewater could be treated in three cycles of adsorption, decreasing the concentrations of Cu(II) from 20 to 0.1 mg/L.
Based on the MUSIC-like algorithm, a novel fourth-order (FO) cumulants algorithm to estimate the ... more Based on the MUSIC-like algorithm, a novel fourth-order (FO) cumulants algorithm to estimate the DOAs of source signals is presented in this paper. The basic idea of the proposed approach is to extend the array response vector and increase its rank to estimate more source signals. As the MUSIC-like algorithm, the algorithm can extend the real array to a virtual
Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing, 2007
ABSTRACT The paper analyzes the effect of timing acquisition methods with multi-hypothesis on the... more ABSTRACT The paper analyzes the effect of timing acquisition methods with multi-hypothesis on the UWB system performance, including the BER and user number tolerance, in the multi- path and multiuser channel environment. To our knowledge, it is the first time to investigate the stability problem about multi-hypothesis timing acquisition schemes. In the multi- path UWB systems, the multi-hypothesis timing acquisition strategy has been considered as the most effective method, which takes advantage of the indoor multipath propagation characteristics and considers more than one hypothesized phase as a good estimate of the true signal phase. That means there exists a multipath set where any a path can be locked on by the receiver. The strategy can contribute to speeding up the timing acquisition process through some efficient search approaches at the cost of timing accuracy. However, it is sure that the relative delay between the locked non-strongest path and the strongest one will have the effect on the system performance. In the paper, we have analyzed the effect of the different relative path delay on the BER and user number tolerance for DS-UWB systems employing the different PN sequences. Numerical results show that both the relative path delay and the cross-correlation performance of the PN sequence can degrade the performance of DS-UWB systems.
International Symposium on Systems and Control in Aerospace and Astronautics, 2006
Rapid synchronization acquisition plays a significant role in the structure design of ultra-wideb... more Rapid synchronization acquisition plays a significant role in the structure design of ultra-wideband (UWB) receiver systems. We propose an improved rapid timing acquisition algorithm for UWB, bit reversal block search (BRBS), by employing a bit reversal technique in the serial block search (SBS) algorithm. The SBS algorithm does not provide the best choice of the search block length. Moreover, when
2006 International Conference on Communication Technology, 2006
ABSTRACT Recently, a very effective peak-to-average power ratio (PAR) reduction scheme based on t... more ABSTRACT Recently, a very effective peak-to-average power ratio (PAR) reduction scheme based on the distribution transform (DT) for OFDM signals is proposed. Key idea of DT is to transform the distribution of the OFDM signal amplitudes into a target distribution, which has limited dynamic range and very low PAR. But, the PAR-reduction performance and the BER performance of DT are conflicting with each other similar to other signal-distortion-type PAR-reduction schemes. In this paper, the trade-off between the PAR and BER performances of DT is addressed. An analysis framework is proposed to select the optimum transform function for DT with minimum consumed energy-to-noise ratio (SNRC). Simulation shows DT with the optimum transform function can obtain about 2dB SNRC gain compared to the original OFDM signal.
Direct blind equalization of single-input-single-output (SISO) infinite-impulse-response (IIR) ch... more Direct blind equalization of single-input-single-output (SISO) infinite-impulse-response (IIR) channels is investigated by oversampling the channel output. Only second-order statistics is required and the channel order need not to be known. We first transform the oversampled channel into a special single-input-multiple-output (SIMO) model. Then a linear prediction approach is applied to partially estimate the model parameters. Based on the estimated parameters, zero-forcing equalizers and MMSE equalizers are developed and their efficiency are evaluated by computer simulations
In conventional orthogonal frequency division multiplexing (OFDM) technique, the subcarriers have... more In conventional orthogonal frequency division multiplexing (OFDM) technique, the subcarriers have uniform spaces. The channel gains of the subcarriers are the uniform samples of the channel frequency response. This method may not be efficient when the channel has variable gains in different subcarriers. In this paper we propose a new multicarrier modulation scheme based on generalized Fourier transform. In the new scheme the channel gains of the subcariers are the samples of the channel frequency response but with nonuniform sampling spaces, which is referred as ldquopseudordquo subcarrier spaces in this paper. When the channel information is available at the transmitter, it is possible to avoid the frequency null by adjusting the pseudo subcarrier space. Computer simulations give some demonstrative examples.
This paper proposes a new method for the simultaneous estimation of the 2D arrival angles and the... more This paper proposes a new method for the simultaneous estimation of the 2D arrival angles and the path delays of emitted user signals. By using the ESPRIT algorithm, we firstly formulate the problem with 3 matrix pencil pairs, where the eigenvalues of the matrix pencils contain the unknown parameters. Then a pairing free algorithm is developed to solve the matrix pencil based 3D estimation problem. The new algorithm results in automatical pairing of the parameters in different pencil and thus avoids a separate pairing operation.
The model of memoryless Gaussian channel with deterministic interference are common in various en... more The model of memoryless Gaussian channel with deterministic interference are common in various engineering applications. In this letter we propose a non-data-aided algorithm for joint measurement of the interference level and the noise power. The algorithm applies an iterative approach based on the maximum likelihood criterion. The Cramer-Rao bound (CRB) is also derived as the performance benchmark. Simulation results show
ABSTRACT This paper considers the resource allocation problem of Space Division Multiple Access (... more ABSTRACT This paper considers the resource allocation problem of Space Division Multiple Access (SDMA)/ Multiple Input Single Output (MISO)/Orthogonal Frequency Division Multiple Access (OFDMA) systems. Equal power allocation (EPA) is used among subcarriers to reduce the complexity of the problem. Furthermore, a novel algorithm called proportional rate greedy (PRG) is proposed to choose users and allocate powers among selected users for each subcarrier. Such EPA-PRG algorithm can be applied to different fairness issues. From simulation, it can both achieve high throughput and ensure the fairness among users without increasing the complexity.
Dynorphin peptides and the kappa-opioid receptor are important in the rewarding properties of coc... more Dynorphin peptides and the kappa-opioid receptor are important in the rewarding properties of cocaine, heroin, and alcohol. We tested polymorphisms of the prodynorphin gene (PDYN) for association with cocaine dependence and cocaine/alcohol codependence. We genotyped six single nucleotide polymorphisms (SNPs), located in the promoter region, exon 4 coding, and 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; untranslated region, in 106 Caucasians and 204 African Americans who were cocaine dependent, cocaine/alcohol codependent, or controls. In Caucasians, we found point-wise significant associations of 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;UTR SNPs (rs910080, rs910079, and rs2235749) with cocaine dependence and cocaine/alcohol codependence. These SNPs are in high linkage disequilibrium, comprising a haplotype block. The haplotype CCT was significantly experiment-wise associated with cocaine dependence and with combined cocaine dependence and cocaine/alcohol codependence (false discovery rate, q=0.04 and 0.03, respectively). We investigated allele-specific gene expression of PDYN, using SNP rs910079 as a reporter, in postmortem human brains from eight heterozygous subjects, using SNaPshot assay. There was significantly lower expression for C allele (rs910079), with ratios ranging from 0.48 to 0.78, indicating lower expression of the CCT haplotype of PDYN in both the caudate and nucleus accumbens. Analysis of total PDYN expression in 43 postmortem brains also showed significantly lower levels of preprodynorphin mRNA in subjects having the risk CCT haplotype. This study provides evidence that a 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;UTR PDYN haplotype, implicated in vulnerability to develop cocaine addiction and/or cocaine/alcohol codependence, is related to lower mRNA expression of the PDYN gene in human dorsal and ventral striatum.
To examine if the genes encoding the pleckstrin homology domain–containing protein gene (PLEKHA1)... more To examine if the genes encoding the pleckstrin homology domain–containing protein gene (PLEKHA1), hypothetical LOC387715/ARMS2 gene, and HtrA serine peptidase 1 gene (HTRA1) located on the long arm of chromosome 10 (10q26 region) confer risk for neovascular age-related macular degeneration (AMD) in an independent or interactive manner when controlling for complement factor H gene (CFH) genotype and smoking exposure.Retrospective matched-pair case–control study.Hospital clinic-based sample of 134 unrelated patients with neovascular AMD who have a sibling with normal maculae (268 subjects).Disease status was ascertained by at least 2 investigators by review of fundus photographs and/or fluorescein angiography according to the Age-Related Eye Disease Study grading scale. If necessary, a home retinal examination was performed (n = 6). A combination of direct sequencing and analysis of 8 highly polymorphic microsatellite markers was used to genotype 33 megabases of the 10q26 region on leukocyte DNA. Smoking history was obtained via a standardized questionnaire and measured in pack-years. The family-based association test, haplotype analysis, multiple conditional logistic regression, and linkage analysis were used to determine significant associations.Neovascular AMD status.Of the 23 variants we identified in the 10q26 region, 6 were significant. Four of the 6 were novel and included 2 genotypes that reduced risk of AMD. Many single-nucleotide polymorphisms (SNPs), including the previously reported variants rs10490924 (hypothetical LOC387715/ARMS2) and rs11200638 (HTRA1), defined 2 significant haplotypes associated with increased risk of neovascular AMD. The coding HTRA1 SNP rs2293870, not part of the significant haplotypes containing rs10490924 and rs11200638, showed as strong an association with increased susceptibility to neovascular AMD. Linkage analysis supported our findings of SNP association (P<10−15). No significant interactions were found between any of the SNPs in the 10q26 and smoking or between these SNPs and CFH genotype.Independent of CFH genotype or smoking history, an individual's risk of AMD could be increased or decreased, depending on their genotype or haplotype in the 10q26 region.
Polyacrylonitrile fiber (PANF) was modified by alcoholysis reaction and the efficiencies of the P... more Polyacrylonitrile fiber (PANF) was modified by alcoholysis reaction and the efficiencies of the PANF and the modified polyacrylonitrile fiber (MPANF) for oil removal were investigated. Fourier transform infrared (FTIR) spectroscopy revealed that new organophilic functional groups were grafted on the fiber surface. Scanning electron microscopy (SEM) showed that the alcoholysis process made the surface of the MPANF rougher than that of the PANF. Oil sorption tests of the PANF and the MPANF for motor oil SAE 30, motor oil SAE 50, and multigrade engine oil (MEO) were carried out in batch tank (in water and in oil without water), and the MPANF showed higher oil sorption capacity compared to the PANF. Dynamic sorption of diesel oil-in-water emulsion (initial oil concentration of 630 mg/dm3) was investigated in coalescing bed. The experiments in the coalescing bed indicated that the MPANF could resist higher interstitial velocity, as compared to the PANF. More than 97% of oil content in the influent stream could be removed by the MPANF bed under the optimum condition. The results indicated that reuse of the PANF as oil sorbent was quite feasible.
A cis-9-octadecenoic acid (OA) surface-modified TiO2 nanoparticle with average diameter of 30nm w... more A cis-9-octadecenoic acid (OA) surface-modified TiO2 nanoparticle with average diameter of 30nm was chemically synthesized. The tribological properties of the prepared OA–TiO2 nanoparticle as an additive in water were evaluated with a four-ball tester. The results show that the OA–TiO2 nanoparticle exhibits good antiwear and friction reduction properties as well as load-carrying capacity. The maximum non-seizure load (PB value) can
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
ABSTRACT A new composite adsorbent, zeolite/cellulose acetate blend (ZCAB) fiber, was prepared by... more ABSTRACT A new composite adsorbent, zeolite/cellulose acetate blend (ZCAB) fiber, was prepared by wet spinning method. The scanning electron micrograph results showed that the zeolite particles were retained and wrapped in the networks of the ZCAB fiber. The adsorption of Cu(II) from aqueous solution by ZCAB fiber was studied in a packed bed. The effects of several parameters, such as the pH of solution, initial metal concentration, bed depth and flow rate, were investigated. The breakthrough data were well described by Thomas model, and the service time at different initial concentrations and flow rates was also predicted by the bed depth service time (BDST) model. The dynamic treatment of electroplating wastewater by the ZCAB fiber bed was also assessed, and the saturated column could be regenerated using HCl solution. About 2.1 L of electroplating wastewater could be treated in three cycles of adsorption, decreasing the concentrations of Cu(II) from 20 to 0.1 mg/L.
Based on the MUSIC-like algorithm, a novel fourth-order (FO) cumulants algorithm to estimate the ... more Based on the MUSIC-like algorithm, a novel fourth-order (FO) cumulants algorithm to estimate the DOAs of source signals is presented in this paper. The basic idea of the proposed approach is to extend the array response vector and increase its rank to estimate more source signals. As the MUSIC-like algorithm, the algorithm can extend the real array to a virtual
Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing, 2007
ABSTRACT The paper analyzes the effect of timing acquisition methods with multi-hypothesis on the... more ABSTRACT The paper analyzes the effect of timing acquisition methods with multi-hypothesis on the UWB system performance, including the BER and user number tolerance, in the multi- path and multiuser channel environment. To our knowledge, it is the first time to investigate the stability problem about multi-hypothesis timing acquisition schemes. In the multi- path UWB systems, the multi-hypothesis timing acquisition strategy has been considered as the most effective method, which takes advantage of the indoor multipath propagation characteristics and considers more than one hypothesized phase as a good estimate of the true signal phase. That means there exists a multipath set where any a path can be locked on by the receiver. The strategy can contribute to speeding up the timing acquisition process through some efficient search approaches at the cost of timing accuracy. However, it is sure that the relative delay between the locked non-strongest path and the strongest one will have the effect on the system performance. In the paper, we have analyzed the effect of the different relative path delay on the BER and user number tolerance for DS-UWB systems employing the different PN sequences. Numerical results show that both the relative path delay and the cross-correlation performance of the PN sequence can degrade the performance of DS-UWB systems.
International Symposium on Systems and Control in Aerospace and Astronautics, 2006
Rapid synchronization acquisition plays a significant role in the structure design of ultra-wideb... more Rapid synchronization acquisition plays a significant role in the structure design of ultra-wideband (UWB) receiver systems. We propose an improved rapid timing acquisition algorithm for UWB, bit reversal block search (BRBS), by employing a bit reversal technique in the serial block search (SBS) algorithm. The SBS algorithm does not provide the best choice of the search block length. Moreover, when
2006 International Conference on Communication Technology, 2006
ABSTRACT Recently, a very effective peak-to-average power ratio (PAR) reduction scheme based on t... more ABSTRACT Recently, a very effective peak-to-average power ratio (PAR) reduction scheme based on the distribution transform (DT) for OFDM signals is proposed. Key idea of DT is to transform the distribution of the OFDM signal amplitudes into a target distribution, which has limited dynamic range and very low PAR. But, the PAR-reduction performance and the BER performance of DT are conflicting with each other similar to other signal-distortion-type PAR-reduction schemes. In this paper, the trade-off between the PAR and BER performances of DT is addressed. An analysis framework is proposed to select the optimum transform function for DT with minimum consumed energy-to-noise ratio (SNRC). Simulation shows DT with the optimum transform function can obtain about 2dB SNRC gain compared to the original OFDM signal.
Direct blind equalization of single-input-single-output (SISO) infinite-impulse-response (IIR) ch... more Direct blind equalization of single-input-single-output (SISO) infinite-impulse-response (IIR) channels is investigated by oversampling the channel output. Only second-order statistics is required and the channel order need not to be known. We first transform the oversampled channel into a special single-input-multiple-output (SIMO) model. Then a linear prediction approach is applied to partially estimate the model parameters. Based on the estimated parameters, zero-forcing equalizers and MMSE equalizers are developed and their efficiency are evaluated by computer simulations
In conventional orthogonal frequency division multiplexing (OFDM) technique, the subcarriers have... more In conventional orthogonal frequency division multiplexing (OFDM) technique, the subcarriers have uniform spaces. The channel gains of the subcarriers are the uniform samples of the channel frequency response. This method may not be efficient when the channel has variable gains in different subcarriers. In this paper we propose a new multicarrier modulation scheme based on generalized Fourier transform. In the new scheme the channel gains of the subcariers are the samples of the channel frequency response but with nonuniform sampling spaces, which is referred as ldquopseudordquo subcarrier spaces in this paper. When the channel information is available at the transmitter, it is possible to avoid the frequency null by adjusting the pseudo subcarrier space. Computer simulations give some demonstrative examples.
This paper proposes a new method for the simultaneous estimation of the 2D arrival angles and the... more This paper proposes a new method for the simultaneous estimation of the 2D arrival angles and the path delays of emitted user signals. By using the ESPRIT algorithm, we firstly formulate the problem with 3 matrix pencil pairs, where the eigenvalues of the matrix pencils contain the unknown parameters. Then a pairing free algorithm is developed to solve the matrix pencil based 3D estimation problem. The new algorithm results in automatical pairing of the parameters in different pencil and thus avoids a separate pairing operation.
The model of memoryless Gaussian channel with deterministic interference are common in various en... more The model of memoryless Gaussian channel with deterministic interference are common in various engineering applications. In this letter we propose a non-data-aided algorithm for joint measurement of the interference level and the noise power. The algorithm applies an iterative approach based on the maximum likelihood criterion. The Cramer-Rao bound (CRB) is also derived as the performance benchmark. Simulation results show
ABSTRACT This paper considers the resource allocation problem of Space Division Multiple Access (... more ABSTRACT This paper considers the resource allocation problem of Space Division Multiple Access (SDMA)/ Multiple Input Single Output (MISO)/Orthogonal Frequency Division Multiple Access (OFDMA) systems. Equal power allocation (EPA) is used among subcarriers to reduce the complexity of the problem. Furthermore, a novel algorithm called proportional rate greedy (PRG) is proposed to choose users and allocate powers among selected users for each subcarrier. Such EPA-PRG algorithm can be applied to different fairness issues. From simulation, it can both achieve high throughput and ensure the fairness among users without increasing the complexity.
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