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Method and apparatus for united demodulation of adjacent channel signals in digital communication system

A channel and signal technology, applied in the direction of digital transmission system, transmission system, baseband system, etc., can solve problems such as limited and narrow application range

Inactive Publication Date: 2004-01-21
TELEFON AB LM ERICSSON (PUBL)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] However, as mentioned above, in terms of spectral efficiency, the effectiveness of using the above systems to reduce and avoid adjacent channel interference is very limited, and their application range is also very narrow

Method used

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  • Method and apparatus for united demodulation of adjacent channel signals in digital communication system
  • Method and apparatus for united demodulation of adjacent channel signals in digital communication system
  • Method and apparatus for united demodulation of adjacent channel signals in digital communication system

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Embodiment Construction

[0022] figure 2 Illustrated is a radio communication system 200 employing the present invention. As shown, the radio system 200 includes a first radio transmitter 202 having a first transmit antenna 206, a second radio transmitter 204 having a second transmit antenna 208, and a radio receiver. The radio receiver has a receiving antenna 210 , a radio frequency processor 211 and a baseband processor 218 . The RF processor 211 has a power divider 212 , a first radio processor 214 and a second radio processor 216 .

[0023] An output of the first radio transmitter 202 is connected to the first transmitting antenna 206 and an output of the second radio transmitter 204 is connected to the second transmitting antenna 208 . The receive antenna 210 is connected to an input of a power divider 212, and an output of the power divider 212 is connected to inputs of a first and a second radio processor 214,216. The outputs of the first and second radio processors 214 , 216 are connected ...

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Abstract

Methods and apparatus for receiving adjacent channel signals wherein adjacent channel interference effects are minimized through joint demodulation of the adjacent channel signals. A channel associated with each signal and each corresponding frequency band is estimated and used to form joint branch metrics for joint sequence estimation. In an exemplary embodiment, a baseband processor receives baseband samples corresponding to at least one carrier frequency, and then jointly demodulates at least two information streams corresponding to different carrier frequencies in dependence upon the received baseband samples. In another embodiment, a joint channel estimator receives at least two baseband sample streams, each stream corresponding to a different frequency band, and jointly estimates medium responses for each of at least two information signals which were transmitted in different frequency bands.

Description

Background of the invention [0001] The present invention relates to digital communication, and more particularly, to a method for demodulating adjacent channel signals in a digital communication system. [0002] A major consideration in all digital communication systems is the channel bandwidth required to transmit information. In general, digital systems are designed to utilize their channel bandwidth as efficiently as possible. For example, in systems using frequency division multiplexing, the highest spectral efficiency can only be obtained with very small channel spacing in the available spectrum. [0003] In practice, however, the minimum carrier frequency spacing is limited by adjacent channel interference. Such as figure 1 As shown, the adjacent channel interference is when the carrier frequency is close enough, after the information signal is modulated on the carrier frequency, the interference caused by two channels overlapping each other on the frequency spectrum....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04J1/12H04B1/10H04B7/26H04L25/02H04L25/03H04W16/02H04W88/02
CPCH04L25/03331H04L25/0204
Inventor H·阿斯兰S·C·古普塔G·E·博顿利S·岑纳克舒
Owner TELEFON AB LM ERICSSON (PUBL)