High Speed Data Transmission Using Expanded Bit Durations in Multiple Parallel Coded Data Streams
The telecommunication industry has produced an explosion of wireless technology. The next generation personal communications networks will need to be able to support a very high level of user traffic along with a wide range of high quality services at varying bit rates. However, the ability for wireless channels to achieve high bit rates at low error rates is severely restricted by multiple transmission paths with different time delays, attenuation, and phasors. Current technology utilises multicarrier modulation or multitone modulation to solve the problem. However, such approaches often require equalization in the frequency domain, which can prove to be quite complex with high transmission rates and time-varying wireless channels. The performance of these systems significantly degrades if the channel feedback information has error.
The invention relates to multicode transmission, which is a new technique and can provide reliable high speed transmission of data over channels that suffer from multipath fading such as in wireless communications. The incoming high-rate data stream is divided into a number of parallel low-rate bit streams as in multitone and multicarrier modulation. The low-rate bit stream using direct-sequence (DS) spread-spectrum on a single carrier. The choice of signature sequences or codes are able to separate the interference between the low-rate bit streams and their multipath duplicates. Therefore, the ratio of system sensitivity to delay spread is reduced because of the spreading of the signaling.
1. Robust to fading and multipath problems without introducing additional equalisation or related circuitry
2. Reliable
3. Without spreading the original bandwidth of the transmitted spread spectrum signal
- Wireless local area networks
- Wireless automatic teller machine (ATM)
- Wireless video terminals
Patent Number: US5960032A
Application Number: US1995531012A
Inventor: Letaief, Khaled Ben | Chuang, Justin C I | Murch, Ross D.
Priority Date: 20 Sep 1995
Priority Number: US5960032A
Application Date: 20 Sep 1995
Publication Date: 28 Sep 1999
IPC Current: H04B0001707 | H04B0007005 | H04B000726
US Class: 375146 | 375206 | 375E01002
Assignee Applicant: The Hong Kong University of Science & Technology
Title: High speed data transmission using expanded bit durations in multiple parallel coded data streams
Usefulness: High speed data transmission using expanded bit durations in multiple parallel coded data streams
Summary: For high speed data transmission in wireless personal communications.
Novelty: Multicode modulation technique for wireless personal communications
信息和通信技术/电信
电信
20 Sep 1995
US 5960032
TTC.PA.023
香港
