Batch distributed sample acquisition for M-ary signaling DS/CDMA systems

In this paper, we propose a batch distributed sample acquisition(BDSA) scheme applicable to a DS/CDMA system employing the Ai-ary signaling for data transmission. While the primitive distributed sample acquisition(DSA) scheme can be employed only for the binary signaling systems which transmit one bit per symbol, the proposed BDSA scheme extends its applicability to the general signaling systems allowing multi-bit transmission per symbol. Since the BDSA contains the primitive DSA as a special case of M=2, it may be regarded as a generalized DSA system. For the construction of the BDSA system, we resort to the igniter sequence concept and the non-uniform sampling and correction scheme of the distributed sample scrambling(DSS). In the BDSA receiver the igniter sequence is synchronized first, which takes very short time due to its short period, and then the state symbol composed of log2M state samples of the transmitter main shift register generator(SRG) is decoded successively and supplied for the synchronization of the receiver main SRG. The DSS technique imbedded in the BDSA scheme enables synchronizing the receiver main SRG in a few state symbol transmissions. Through a design study we confirm that the BDSA scheme contributes to speeding up the acquisition time as well as to saving the hardware cost by enabling the reuse of the data transceiver circuitry for the synchronization process.