Signal-to-Interference Ratio(SIR) is a very important metric of communication link quality. For wireless cellular systems, several control mechanisms, such as power control mechanisms, rate control mechanisms, and all...Signal-to-Interference Ratio(SIR) is a very important metric of communication link quality. For wireless cellular systems, several control mechanisms, such as power control mechanisms, rate control mechanisms, and allocation of radio resource, are based on SIR estimation.In previous researches, most of researchers concentrated on WCDMA systems, in which pilot symbol is time-multiplexed with data symbol; the method developed in this case is not feasible for cdma2000 systems where pilot symbol is code-multiplexed with data symbol. This paper first develops the SIR estimators based on the reverse pilot channel and then derives the approximate analytic expression for its Mean Squared Error (MSE) function, the accuracy of which is validated through simulation. It is shown that the MSE of the new SIR estimator is significantly smaller than that of other widely used SIR estimators, especially in low SIR case. Finally, the estimate quality of the proposed method is further improved by long-termly averaging the sample interference.展开更多
A new carrier frequency offset estimation scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems is proposed. The carrier frequency offset estimation includes acquisition and tracking. The acquisition ra...A new carrier frequency offset estimation scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems is proposed. The carrier frequency offset estimation includes acquisition and tracking. The acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth. Comparison of the proposed scheme with Schmidl's algorithm by computer simulation illustrates the superior performance of the proposed scheme with regard to estimation accuracy in both AWGN channel and multipath channels.展开更多
In order to maximize the average throughput and minimize the transmissionslot delay in wireless Ad Hoc networks, an optimal topology-transparent transmission schedulingalgorithm-multichannel Time-Spread Multiple Acces...In order to maximize the average throughput and minimize the transmissionslot delay in wireless Ad Hoc networks, an optimal topology-transparent transmission schedulingalgorithm-multichannel Time-Spread Multiple Access (TSMA) is proposed. Further analysis is shownthat the maximum degree is very sensitive to the network performance for a wireless Ad Hoc networkswith N mobile nodes. Moreover, the proposed multichannel TSMA can improve the average throughput Mtimes and decrease the average transmission slot delay M times, as compared with singlechannel TSMAwhen M channels are available.展开更多
文摘Signal-to-Interference Ratio(SIR) is a very important metric of communication link quality. For wireless cellular systems, several control mechanisms, such as power control mechanisms, rate control mechanisms, and allocation of radio resource, are based on SIR estimation.In previous researches, most of researchers concentrated on WCDMA systems, in which pilot symbol is time-multiplexed with data symbol; the method developed in this case is not feasible for cdma2000 systems where pilot symbol is code-multiplexed with data symbol. This paper first develops the SIR estimators based on the reverse pilot channel and then derives the approximate analytic expression for its Mean Squared Error (MSE) function, the accuracy of which is validated through simulation. It is shown that the MSE of the new SIR estimator is significantly smaller than that of other widely used SIR estimators, especially in low SIR case. Finally, the estimate quality of the proposed method is further improved by long-termly averaging the sample interference.
文摘A new carrier frequency offset estimation scheme for Orthogonal Frequency-Division Multiplexing (OFDM) systems is proposed. The carrier frequency offset estimation includes acquisition and tracking. The acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth. Comparison of the proposed scheme with Schmidl's algorithm by computer simulation illustrates the superior performance of the proposed scheme with regard to estimation accuracy in both AWGN channel and multipath channels.
基金This work is supported by"863"High Technology Development Project Fund (No.2003AA12331004).
文摘In order to maximize the average throughput and minimize the transmissionslot delay in wireless Ad Hoc networks, an optimal topology-transparent transmission schedulingalgorithm-multichannel Time-Spread Multiple Access (TSMA) is proposed. Further analysis is shownthat the maximum degree is very sensitive to the network performance for a wireless Ad Hoc networkswith N mobile nodes. Moreover, the proposed multichannel TSMA can improve the average throughput Mtimes and decrease the average transmission slot delay M times, as compared with singlechannel TSMAwhen M channels are available.
