{"title":"Performance analysis of a correlator based maximum likelihood frequency estimator","authors":"S. Kandeepan, S. Reisenfeld","doi":"10.1109/SPCOM.2004.1458379","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458379","url":null,"abstract":"In this paper we discuss the performance of a correlator based frequency estimator (CE). The estimator is statistically analysed for single-tone frequency estimation for an additive white Gaussian noise (AWGN) channel. The CE is a maximum likelihood estimator (ML) S. M. Kay (1993) which theoretically achieves the Cramer-Rao lower bound (CRB) S. M. Kay (1993) if properly implemented. Frequency estimates on the received single-tone signal are made by correlating the received signal with a locally generated signal by varying the frequency, and maximizing the energy at the output of the correlator. The statistical distribution of the frequency estimates, made by the CE is studied; we consider four different cases as discussed in the paper for the distribution, whilst providing simulation results to verify the analysis.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132393180","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}
{"title":"Bounds on MMSE multiuser detection for CDMA","authors":"A. Kohli, D. K. Mehra","doi":"10.1109/SPCOM.2004.1458365","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458365","url":null,"abstract":"Minimum-mean-square-error (MMSE) linear multiuser detector considers multiple access interference (MAI) and background noise asymptotically Gaussian for large number of users in asynchronous code division multiple access (CDMA) system. For this asymptotic condition, the available results in literature have been derived for two-user case. In this paper, we have proposed a general formula to calculate upper bound on normalized cross-correlation (NCC) for arbitrary number of users. Under near-far situation, Chernoff upper bound on error probability of MMSE multiuser detector is presented. Its proof based on divergence theorem and study of leakage coefficients imposes minimum bound on signal-to-noise ratio of desired user (SNRD).","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128616814","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}
{"title":"Performance of transmit diversity scheme with quantized phase-only feedback","authors":"J. Klutto Milleth, K. Giridhar, D. Jalihal","doi":"10.1109/SPCOM.2004.1458393","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458393","url":null,"abstract":"Closed-loop (feedback) rate-one channel orthogonalized space-time block codes (CO-STBCs) for 3 and 4 transmit antennas using a single (real) phase feedback are proposed. These codes with ideal feedback achieve full diversity and result in maximum likelihood (ML) decoding with only linear processing at the receiver. In this paper, we study the impact on the error-rate performance when the feedback phase information is quantized. Simulation results suggest that there is a significant SNR advantage even when only one bit is used to represent the phase feedback term. Also, it is found that three bits are sufficient to obtain nearly the ideal feedback performance.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125782257","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}
{"title":"Computationally efficient blind multiuser detection for multipath CDMA channels","authors":"C. K. Ali, E. Gopinathan","doi":"10.1109/SPCOM.2004.1458368","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458368","url":null,"abstract":"In this paper a blind, adaptive minimum mean squared error (MMSE) receiver, which jointly performs data detection and channel estimation for multipath CDMA channels, is considered. The receiver is implemented using the constrained minimum output energy (MOE) criterion and the least mean square (LMS) algorithm. The computational complexity of the proposed receiver is only of order N (O(N)) per symbol, where N is the processing gain. The proposed receiver requires only the signature code of the user of interest (UOI) and does not require any training sequences, the channel parameters of any users and signature codes of the interfering users (Timing information is assumed to be known by the receiver). Though the channel parameters of the UOI are not explicitly calculated, the energies of multiple paths are advantageously combined as done in a conventional RAKE receiver. Here multiple access interference (MAI) is first removed and SNR is subsequently maximized using the min-max principle. The bit-error performance of the proposed receiver closely approaches that of the non-blind, non-adaptive MMSE detector. We are also introducing a blind, adaptive, decorrelating receiver, which can be obtained even when noise is zero.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125240574","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}
{"title":"An alternative representation of speech using the modified group delay feature","authors":"R.M. Hedge, H. Murthy","doi":"10.1109/SPCOM.2004.1458402","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458402","url":null,"abstract":"Representation of speech is complete when both the Fourier transform magnitude and phase spectra are used to extract features. But speech is conventionally represented by features derived from the Fourier transform magnitude spectra. In this paper, we propose an alternative representation of speech which uses the modified group delay function derived from the Fourier transform phase spectra. Cepstral features are derived from the modified group delay function. These features are called the modified group delay feature (MODGDF). Robustness of the MODGDF to convolutional and additive noise are then analyzed mathematically. Class separability and task independence of the MODGDF is then illustrated via the sequential forward search feature selection method. The results of performance evaluation of the MODGDF for four speech processing tasks phoneme recognition, syllable recognition, speaker identification, and language identification are presented. Motivated by the results of feature evaluation and performance evaluation, the MODGDF is proposed as an alternative representation of speech.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127232538","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}
{"title":"Using rate matching attributes for differentiated QoS in UMTS networks","authors":"R. Karthik, J. Kuri","doi":"10.1109/SPCOM.2004.1458493","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458493","url":null,"abstract":"We consider I transport channels on the downlink of an UMTS network, with rate matching attribute (RMA) values RMA/sub 1/, RMA/sub 2/,...RMA/sub I/, that are multiplexed on a single coded composite transport channel (CCTrCh). We derive analytical expressions for the bit error ratios (BERs) seen by each channel in the multiplex. Simulations indicate that the expressions are very accurate. We also provide a procedure that gives the RMA values required to achieve a target set of BERs for a specified signal-to-noise ratio; when no feasible RMA values exist, the procedure indicates that as well. The results of this paper will be of use to UMTS service providers who wish to provide differentiated QoS while maintaining high spectral efficiency.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116839744","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}
{"title":"Continuous waveforms from a binary modulator","authors":"Jagadish Venkataraman, O. Collins","doi":"10.1109/SPCOM.2004.1458497","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458497","url":null,"abstract":"This paper explains how a low rate purely digital code labeling a trellis encodes representative RF signals as needed for wireless communications. This new approach allows for a completely digital transmitter i.e. there are no analog stages required for up-conversion. The binary stream coming out of a finite state machine is simply filtered and then directly radiated. GMSK is used as a motivating example and typical SNR values and data rates achieved are presented; however, other modulation schemes can be equally well represented using this technique.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126879018","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}
{"title":"Low-computation and high-performance adaptive full search block-matching motion estimation","authors":"V. Reddy, S. Sengupta","doi":"10.1109/SPCOM.2004.1458413","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458413","url":null,"abstract":"This paper describes a low-computation and high-performance adaptive full search block matching (FSBM) by exploiting the spatio-temporal motion correlation between the video frames. In this work, previous frame block motion vector is the reference vector to track the motion of the current block. We also investigate the advantages of partial distortion measures for early jump outs to reduce the computations further. The experimental results reveal that the proposed adaptive search area FSBM algorithm (ASFSBM) saves up to 96% of computations, as compared to FSBM and the estimation accuracy is very close to that of FSBM. To obtain fine motion vector accuracy, ASFSBM has been implemented with half-pixel accuracy. Its performance has been compared with three-step search (TSS) and FSBM for a variety of test video sequences.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124546752","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}
{"title":"Achieving delay differentiation by scheduling based on optimal balancing of weighted instantaneous and cumulative queue lengths","authors":"A. Chakraborty, U. Mukherji","doi":"10.1109/SPCOM.2004.1458432","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458432","url":null,"abstract":"Scheduling policies for statistical multiplexing should provide delay differentiation between different traffic classes, where each class represents an aggregate traffic of individual applications having the same target queueing delay requirements. We propose scheduling to optimally balance weighted queue lengths as an approach to delay differentiation, class weights being set inversely proportional to the respective products of target delays and packet arrival rates. We formulate the problem in the framework of Markov decision theory, assuming a discrete-time, two-class, single-server queueing model with unit service time per packet. We first find a scheduling policy based on weighted instantaneous queue lengths, for the case of Bernoulli packet arrivals, that minimizes the stationary mean of the absolute value of the difference of the weighted instantaneous queue lengths. We then find a scheduling policy based on weighted cumulative queue lengths, for the case of i.i.d. packet batch arrivals, that achieves target mean queueing delays in simulation.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130306104","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}
{"title":"A class of antenna dynamic selection algorithm based on E/sub b//I/sub 0/ in DWCS","authors":"Chen Peng, Li Zheng, Wu Wei-ling","doi":"10.1109/SPCOM.2004.1458398","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458398","url":null,"abstract":"In this paper a class of antenna dynamic selection (ADS) algorithm for CDMA distributed wireless communication system (DWCS) is proposed. In our algorithm, the number of antennas involved in a \"virtual cell\" (VC) is adjusted dynamically based on the rule of keeping just fit number of antennas in the VC instead of the common adopted antenna static selection (ASS) method that each VC contains same number of antennas. Our investigation shows that E/sub b//I/sub 0/-based ADS is a cost-effective solution in the interference-limited environment because it achieves almost similar outage capacity as ASS while reducing antenna costs significantly than that of ASS in both underloaded and overloaded systems.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"248 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126829122","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}