Refine
Year of publication
- 2007 (3) (remove)
Document Type
Conference Type
- Konferenzartikel (1)
Language
- English (3)
Has Fulltext
- no (3) (remove)
Is part of the Bibliography
- yes (3) (remove)
Keywords
- CDMA (2)
- Codierung (1)
- Verteilung (1)
Institute
- Fakultät Elektrotechnik und Informationstechnik (E+I) (bis 03/2019) (3) (remove)
Open Access
- Closed Access (3) (remove)
Design of next-generation cdma using orthogonal complementary codes and offset stacked spreading
(2007)
This article presents an innovative code-division multiple access system architecture that is based on orthogonal complementary spreading codes and time-frequency domain spreading. The architecture has several advantages compared to conventional CDMA systems. Specifically, it offers multiple-access-interference-free operation in AWGN channels, reduces co-channel interference significantly, and has the potential for higher capacity and spectral efficiency than conventional CDMA systems. This is accomplished by using an "offset stacked" spreading modulation technique followed by quadrature amplitude modulation, which optimizes performance in a fading environment. This new spreading modulation scheme also simplifies the rate matching algorithms relevant for multimedia services and IP-based applications.
A new, small, and optimized for low power processor core named SIRIUS has been developed, simulated, synthesized to a netlist and verified. From this netlist, containing only primitives like gates and flip-flops, a mapping to an ASIC - or FPGA technology can easily be done with existing synthesizer tools, allowing very complex SOC designs with several blocks. Emulation via FPGA can be done on already simple setups and cheap hardware because of the small core size. The performance is estimated 50 MIPS on Cyclone II FPGA and about 100 MIPS on a 0.35 CMOS 5M2P technology with 4197 primitives used for the core, including a 16 x 16 multiplier. An example design of the ASIC for an electronic ePille device currently in development is shown.
This paper presents a multicarrier code-division multiple-access (CDMA) system architecture that is based on complete complementary orthogonal spreading codes. The architecture has several advantages as compared to conventional CDMA systems. Specifically, it offers multiple-access interference-free operation in additive white Gaussian noise channels, reduces cochannel interference significantly, and has the potential of higher capacity and spectral efficiency than conventional CDMA systems. This is accomplished by using an ldquooffset stackedrdquo spreading modulation technique. To maintain good performance in the presence of fading, the offset stacked modulator is followed by a quadrature-amplitude modulation map, which is designed to optimize performance in a fading environment. This new modulation scheme also simplifies the rate-matching algorithms that are relevant for multimedia services and Internet Protocol-based applications.