Multi-user MIMO CDMA systems using complete complementary sequences

Abstract

The authors propose a novel use of complete complementary (CC) sequences for increased spectral efficiency in a multiple-input-multiple-output (MIMO) code division multiple access (CDMA) system. The new method overcomes many of the problems and limitations persistent in single-input-single-output (SISO) and proves that under the proposed MIMO CC-CDMA system, the capacity for the number of supported users increases linearly by the number of transmitters. The paper also shows that the MIMO CC-CDMA system demonstrates a superior performance over those using traditional Walsh spreading sequences (Walsh-CDMA). Results include the bit error rate comparison for CC-CDMA frequency selective fading channels and that of the Walsh-CDMA under flat fading channels.

Stereo Image Transmission over Fading Channels with Multiterminal Source Coding

“…For generation of CC sequences refer to [8], [19]. The MC-CDMA system of [8], [19] uses offset stacked (OS) spreading modulation technique which enables multirate transmission, without the need for complex rate matching algorithm.…”

“…The MC-CDMA system of [8], [19] uses offset stacked (OS) spreading modulation technique which enables multirate transmission, without the need for complex rate matching algorithm. This makes CC sequences very attractive for multimedia services with variable rate requirements to which rate change can be made scalable and continuous.…”

“…CC sequences are proposed as substitute to the currently used CDMA spreading sequences (such as Gold, Walsh Hadamard, and m-sequences), which lose their mutual orthogonality, under asynchronous multipath fading channels, which results in interference-limited system performance. CC sequences, on the other hand, maintain their orthogonality (under such channel conditions), which is based on a whole set of sequences instead of a single sequence, and results in improved system performance [10], [19].…”

Compress-spread-forward with multiterminal source coding and complete complementary sequences

“…In [9,26] CC codes are used for spreading in the downlink, i.e., from the single station to multiple users. In our setup, spreading is done at the two BS (which play the role of the users) to a single mobile client.…”

“…Thus, we have an uplink communications problem. We modify the system of [26] to enable multiple access in uplink. Each BS is assigned its own unique set of spreading sequences.…”