Showing papers by "Amitava Ghosh published in 2000"

Multi channel stop and wait arq communication method and apparatus

Abstract: A method in a communication system (100) includes transmitting from a source user (101) a first data packet (111) over a first time frame (121) having a finite time period (131), transmitting from source user (101) a second data packet (112) over a second time frame (122) immediately subsequent to first time frame (121), detecting an acknowledgment of acceptable reception of data packet associated with either first or said second data packets (111 and 112), repeating transmission of first and second data packets (111 and 112) in a sequence of first and second time frames (121 and 122) in a time frame sequence (190) until the detection.

Variable rate spread spectrum communication method and apparatus

Abstract: A communication system (100) provides selecting a first modulation-coding scheme (111), determining a first possible number of data bits (201), determining a first number of data (102) to be transmitted from the source user to the first destination user, and determining a first load level. If the first load level is unequal to a whole number, rounding to a next first whole number, selecting a first number of plurality of spreading codes (108-1 through 108-k) based on the first whole number of load level for spread coding of first number of data bits (102) after being modulated and coded according to selected modulation-coding scheme (111).

Performance of coded higher order modulation and hybrid ARQ for next generation cellular CDMA systems

Abstract: A key requirement for next generation CDMA systems is to provide a high bit rate packet data service and improved sector throughput for both low and high mobility applications. A 1.25 MHz DS-CDMA evolution called 1XTREME (Third Generation Enhanced Modulation and Encoding) has been proposed. 1XTREME uses a forward shared channel (F-SHCH) that is shared by multiple packet data users and is capable of supporting peak rates of up to 5 Mbps, compared to third generation CDMA system indoor peak data rates of 460 kbps and 2 Mbps for IS-2000 and W-CDMA, respectively. In this paper the link performance of the F-SHCH is evaluated for different modulation and coding scheme (MCS) configurations. Based on the link results, the average sector throughput is presented for two simple scheduling algorithms, as well as performance as a function of the maximum allowed FER operating point.